[1] Which of the following is a good conductor of heat but a bad conductor of electricity?
A.
Celluloid
B.
Rubber
C.
Asbestos
D.
Mica
Ans:
Mica
Explanation :
Good conductors of heat are good conductors of electricity. Mica is an exception which although being a good conductor of heat and a bad conductor of electricity. It is commonly used in insulation of electricity between high heat generating transistors and their heat sink and or chassis to prevent grounding out of component and to assist in the transfer of the generated heat to the heat sink or chassis for dissipation.
[2] A piece of wood is held under water. The up thrust on it will be:
A.
equal to the weight of the Wood
B.
less than weight of the wood
C.
more than weight of the wood
D.
Zero
Ans:
less than weight of the wood
Explanation :
According to the Archimedes' principle, a floating object will experience an up thrust force from water, equal to the weight of water displaced (pushed aside). It will sink into the water until it reaches the point where the weight of the water pushed aside equals its own weight.
[3] In MRI machine, which one of the following is used?
A.
Sound wave
B.
X-ray
C.
Ultra-sound wave
D.
Magnetic wave
Ans:
Magnetic wave
Explanation :
Magnetic resonance imaging (MRI), nuclear magnetic resonance imaging (NMRI), or magnetic resonance tomography (MRT) is a medical imaging technique used in radiology to visualize internal structures of the body in detail. MRI makes use of the property of nuclear magnetic resonance (NMR) to image nuclei of atoms inside the body.
[4] For a person having hypermetropia, the near point is –
A.
greater than 25 cm
B.
greater than 50 cm
C.
less than 25 cm
D.
infinity
Ans:
greater than 25 cm
Explanation :
For a hyper-metropic eye, the near points shift away from the eye i.e. farther away from the normal near point (25cm). In a hypermetropic eye, the light is not bent sufficiently so that it focuses at a point behind the retina. Here a person sees well for distance but near vision is difficult and causes strain. Hence hypermetropic people are called long-sighted. To correct the hypermetropic eye, a plus lens is required so that the light can now focus on the retina.
[5] Amount of water vapour in the atmosphere is measured in terms of –
A.
Humidity
B.
Droplets
C.
Smog
D.
All of the above
Ans:
Humidity
Explanation :
Humidity is the amount of water vapor in the air. Water vapor is the has phase of water and is invisible. Humidity indicates the likelihood of precipitation, dew, or fog. Higher humidity reduces the effectiveness of sweating in cooling the body by reducing the rate of evaporation of moisture from the skin.
[6] Name the process of production of energy in the Sun –
A.
Nuclear fission
B.
Radioactivity
C.
Nuclear fusion
D.
Ionization
Ans:
Nuclear fusion
Explanation :
The source of the sun's fuel is hydrogen and helium gases. Through a special chemical reaction, called nuclear fusion, the hydrogen gas is "burned" releasing an enormous amount of energy in the form of light and heat.
[7] The ozone hole that has been detected lies in the atmosphere above –
A.
Arctic Ocean
B.
Antarctica
C.
India
D.
Alaska
Ans:
Antarctica
Explanation :
Ozone layer, that is, the layer of life-protecting ozone found at the top of the stratosphere. Ozone is formed in the earth's stratosphere and is critical to life on earth as we know it. There is compelling scientific evidence that ozone is destroyed in the stratosphere and that some human-released chemicals are speeding up the breakdown of ozone in the atmosphere.
[8] The device used to change the speed of an electric fan is –
A.
Amplifier
B.
Regulator
C.
Switch
D.
Rectifier
Ans:
Regulator
Explanation :
A voltage regulator is designed to automatically maintain a constant voltage level. A voltage regulator maybe a simple "feed-forward" design or may include negative feedback control loops. It may use an electromechanical mechanism, or electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages. Electronic voltage regulators are found in devices such as computer power supplies where they stabilize the DC voltages used by the processor and other elements.
[9] Which one of the following wave-lengths of light is most effective in photosynthesis?
A.
Blue
B.
Green
C.
Orange
D.
Yellow
Ans:
Blue
Explanation :
Photosynthesis, process by which green plants and certain other organisms use the energy of light to convert carbon dioxide and water into the simple sugar glucose. The wavelength most effective in conducting photosynthesis is 420nm. Actually, 420nrn is on the blue side of the spectrum, which makes up between 1 and 10% of the light needed for photosynthesis.
[10] Why is it difficult to breathe at higher altitudes?
A.
Due to low air pressure
B.
Due to low temperature
C.
Due to ozone
D.
Due to high humidity
Ans:
Due to low air pressure
Explanation :
Low air pressure is usually the most significant limiting factor in high mountain regions. The percentage of oxygen in the air at 3.2 km is essentially the same as at sea level (21%). However, the air pressure is 30% lower at the higher altitude due to the fact that the atmosphere is less dense—that is the air molecules are farther apart. At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our vascular systems.
[11] The reason for a swimming pool to appear less deep than the actual depth is –
A.
Refraction
B.
Light scattering
C.
Reflection
D.
Interference
Ans:
Refraction
Explanation :
The apparent depth will look less that its real depth due to the refraction of light. Refraction is the bending of a wave when it enters a medium where it's speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law.
[12] Alternating current is converted into direct current by a –
A.
Transformer
B.
Dynamo
C.
Oscillator
D.
Rectifier
Ans:
Rectifier
Explanation :
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification.
[13] Remote-sensing device has an inbuilt source of –
A.
X-ray
B.
g-ray
C.
Ultraviolet ray
D.
Infrared ray
Ans:
Infrared ray
Explanation :
Infrared imaging is used extensively for military and civilian purposes. Military applications include target acquisition, surveillance, night vision, homing and tracking. Non-military uses include thermal efficiency analysis, environmental monitoring, industrial facility inspections, remote temperature sensing, short-ranged wireless communication, spectroscopy, and weather forecasting.
[14] The atmosphere is heated mainly by –
A.
Insulation
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
Changes in weather involve air movements, formation of clouds, and precipitation. Energy is needed to make all these things happen. That energy comes from the sun. Heat energy enters and moves through the atmosphere in three different ways. One way that heat energy is transferred is radiation. Hot bodies such as the sun radiate their energy mainly in the form of short waves.
[15] The atmospheric layer reflecting radio waves is called –
A.
Ozonosphere
B.
Ionosphere
C.
Stratosphere
D.
Mesosphere
Ans:
Ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere, from about 85 km to 600 km altitude, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth.
[16] 'Cryogenics' is a science dealing with –
A.
high temperatures
B.
low temperatures
C.
friction and wear
D.
growth of crystals
Ans:
low temperatures
Explanation :
Cryogenics is the study of how to get to low temperatures and of how materials behave when they get there. Besides the familiar temperature scales of Fahrenheit and Celsius (Centigrade), cryogenicists use other temperature scales, the Kelvin and Rankine temperature scales. One of the more modern processes being used to treat metals (as well as other materials) is cryogenic tempering.
[17] Heat from the Sun reaches the Earth by –
A.
Reflection
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
The radiation (light, heat, etc.) travels through the intervening 150,000,000 kilometers in 8 minutes. Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. Waves of a massive medium itself, such as water waves or sound waves, are usually not considered to be forms of "radiation" in this sense.
[18] The commonly used thermometric substance is _.
A.
mineral oil
B.
Alcohol
C.
Mercury
D.
Petrol
Ans:
Mercury
Explanation :
Thermometric liquids are used in thermometers to measure temperature. Mercury and alcohol are common thermometric liquids.
[19] Gamma rays can cause –
A.
gene mutation
B.
sneezing
C.
burning
D.
fever
Ans:
gene mutation
Explanation :
In molecular biology and genetics, mutations are accidental changes in a genomic sequence of DNA: the DNA sequence of a cell's genome or the DNA or RNA sequence in some viruses. These random sequences can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that, occur during meiosis or DNA replication.
[20] The dimension of which of the following is the same as that of impulse?
A.
Volume
B.
Momentum
C.
Torque
D.
Change in the rate of momentum
Ans:
Momentum
Explanation :
The quantity of impulse is force x time interval. In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter or moving slower, then it would have less momentum.
[21] Which among the following is the fundamental quantity?
A.
Volume
B.
Time
C.
Velocity
D.
Force
Ans:
Time
Explanation :
The fundamental qualities of Physics are the seven basic quantities that can be used to express all other physical quantities. These are as follows: Length: Metre, Heat: Kelvin, Time: second, Luminous Intensity: Candela, Mass: Kilogram, Electric Current: Ampere, and Amount of substance: Moles.
[22] Global warming is expected to result in –
A.
Increase in level of sea
B.
Change in crop pattern
C.
Change in coast line
D.
All of the above
Ans:
All of the above
Explanation :
Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a probable expansion of subtropical deserts.
[23] A transformer works on the principle of –
A.
Self induction
B.
Mutual induction
C.
Generator
D.
Inverter
Ans:
Mutual induction
Explanation :
A transformer is a power converter that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.
[24] Who defined the law of gravitation?
A.
Newton
B.
Archimedes
C.
Galileo
D.
Faraday
Ans:
Newton
Explanation :
Sir Isaac Newton brought out his monograph, titled ‘Philosophiæ Naturalis Principia Mathematica,’ in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. Newton’s law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
[25] Which of the following parts of the sunlight makes the solar cooker hot?
A.
Ultra violet
B.
Red light
C.
Infra red
D.
Cosmic rays
Ans:
Infra red
Explanation :
Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.
Explanation :
Good conductors of heat are good conductors of electricity. Mica is an exception which although being a good conductor of heat and a bad conductor of electricity. It is commonly used in insulation of electricity between high heat generating transistors and their heat sink and or chassis to prevent grounding out of component and to assist in the transfer of the generated heat to the heat sink or chassis for dissipation.
[2] A piece of wood is held under water. The up thrust on it will be:
A.
equal to the weight of the Wood
B.
less than weight of the wood
C.
more than weight of the wood
D.
Zero
Ans:
less than weight of the wood
Explanation :
According to the Archimedes' principle, a floating object will experience an up thrust force from water, equal to the weight of water displaced (pushed aside). It will sink into the water until it reaches the point where the weight of the water pushed aside equals its own weight.
[3] In MRI machine, which one of the following is used?
A.
Sound wave
B.
X-ray
C.
Ultra-sound wave
D.
Magnetic wave
Ans:
Magnetic wave
Explanation :
Magnetic resonance imaging (MRI), nuclear magnetic resonance imaging (NMRI), or magnetic resonance tomography (MRT) is a medical imaging technique used in radiology to visualize internal structures of the body in detail. MRI makes use of the property of nuclear magnetic resonance (NMR) to image nuclei of atoms inside the body.
[4] For a person having hypermetropia, the near point is –
A.
greater than 25 cm
B.
greater than 50 cm
C.
less than 25 cm
D.
infinity
Ans:
greater than 25 cm
Explanation :
For a hyper-metropic eye, the near points shift away from the eye i.e. farther away from the normal near point (25cm). In a hypermetropic eye, the light is not bent sufficiently so that it focuses at a point behind the retina. Here a person sees well for distance but near vision is difficult and causes strain. Hence hypermetropic people are called long-sighted. To correct the hypermetropic eye, a plus lens is required so that the light can now focus on the retina.
[5] Amount of water vapour in the atmosphere is measured in terms of –
A.
Humidity
B.
Droplets
C.
Smog
D.
All of the above
Ans:
Humidity
Explanation :
Humidity is the amount of water vapor in the air. Water vapor is the has phase of water and is invisible. Humidity indicates the likelihood of precipitation, dew, or fog. Higher humidity reduces the effectiveness of sweating in cooling the body by reducing the rate of evaporation of moisture from the skin.
[6] Name the process of production of energy in the Sun –
A.
Nuclear fission
B.
Radioactivity
C.
Nuclear fusion
D.
Ionization
Ans:
Nuclear fusion
Explanation :
The source of the sun's fuel is hydrogen and helium gases. Through a special chemical reaction, called nuclear fusion, the hydrogen gas is "burned" releasing an enormous amount of energy in the form of light and heat.
[7] The ozone hole that has been detected lies in the atmosphere above –
A.
Arctic Ocean
B.
Antarctica
C.
India
D.
Alaska
Ans:
Antarctica
Explanation :
Ozone layer, that is, the layer of life-protecting ozone found at the top of the stratosphere. Ozone is formed in the earth's stratosphere and is critical to life on earth as we know it. There is compelling scientific evidence that ozone is destroyed in the stratosphere and that some human-released chemicals are speeding up the breakdown of ozone in the atmosphere.
[8] The device used to change the speed of an electric fan is –
A.
Amplifier
B.
Regulator
C.
Switch
D.
Rectifier
Ans:
Regulator
Explanation :
A voltage regulator is designed to automatically maintain a constant voltage level. A voltage regulator maybe a simple "feed-forward" design or may include negative feedback control loops. It may use an electromechanical mechanism, or electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages. Electronic voltage regulators are found in devices such as computer power supplies where they stabilize the DC voltages used by the processor and other elements.
[9] Which one of the following wave-lengths of light is most effective in photosynthesis?
A.
Blue
B.
Green
C.
Orange
D.
Yellow
Ans:
Blue
Explanation :
Photosynthesis, process by which green plants and certain other organisms use the energy of light to convert carbon dioxide and water into the simple sugar glucose. The wavelength most effective in conducting photosynthesis is 420nm. Actually, 420nrn is on the blue side of the spectrum, which makes up between 1 and 10% of the light needed for photosynthesis.
[10] Why is it difficult to breathe at higher altitudes?
A.
Due to low air pressure
B.
Due to low temperature
C.
Due to ozone
D.
Due to high humidity
Ans:
Due to low air pressure
Explanation :
Low air pressure is usually the most significant limiting factor in high mountain regions. The percentage of oxygen in the air at 3.2 km is essentially the same as at sea level (21%). However, the air pressure is 30% lower at the higher altitude due to the fact that the atmosphere is less dense—that is the air molecules are farther apart. At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our vascular systems.
[11] The reason for a swimming pool to appear less deep than the actual depth is –
A.
Refraction
B.
Light scattering
C.
Reflection
D.
Interference
Ans:
Refraction
Explanation :
The apparent depth will look less that its real depth due to the refraction of light. Refraction is the bending of a wave when it enters a medium where it's speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law.
[12] Alternating current is converted into direct current by a –
A.
Transformer
B.
Dynamo
C.
Oscillator
D.
Rectifier
Ans:
Rectifier
Explanation :
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification.
[13] Remote-sensing device has an inbuilt source of –
A.
X-ray
B.
g-ray
C.
Ultraviolet ray
D.
Infrared ray
Ans:
Infrared ray
Explanation :
Infrared imaging is used extensively for military and civilian purposes. Military applications include target acquisition, surveillance, night vision, homing and tracking. Non-military uses include thermal efficiency analysis, environmental monitoring, industrial facility inspections, remote temperature sensing, short-ranged wireless communication, spectroscopy, and weather forecasting.
[14] The atmosphere is heated mainly by –
A.
Insulation
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
Changes in weather involve air movements, formation of clouds, and precipitation. Energy is needed to make all these things happen. That energy comes from the sun. Heat energy enters and moves through the atmosphere in three different ways. One way that heat energy is transferred is radiation. Hot bodies such as the sun radiate their energy mainly in the form of short waves.
[15] The atmospheric layer reflecting radio waves is called –
A.
Ozonosphere
B.
Ionosphere
C.
Stratosphere
D.
Mesosphere
Ans:
Ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere, from about 85 km to 600 km altitude, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth.
[16] 'Cryogenics' is a science dealing with –
A.
high temperatures
B.
low temperatures
C.
friction and wear
D.
growth of crystals
Ans:
low temperatures
Explanation :
Cryogenics is the study of how to get to low temperatures and of how materials behave when they get there. Besides the familiar temperature scales of Fahrenheit and Celsius (Centigrade), cryogenicists use other temperature scales, the Kelvin and Rankine temperature scales. One of the more modern processes being used to treat metals (as well as other materials) is cryogenic tempering.
[17] Heat from the Sun reaches the Earth by –
A.
Reflection
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
The radiation (light, heat, etc.) travels through the intervening 150,000,000 kilometers in 8 minutes. Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. Waves of a massive medium itself, such as water waves or sound waves, are usually not considered to be forms of "radiation" in this sense.
[18] The commonly used thermometric substance is _.
A.
mineral oil
B.
Alcohol
C.
Mercury
D.
Petrol
Ans:
Mercury
Explanation :
Thermometric liquids are used in thermometers to measure temperature. Mercury and alcohol are common thermometric liquids.
[19] Gamma rays can cause –
A.
gene mutation
B.
sneezing
C.
burning
D.
fever
Ans:
gene mutation
Explanation :
In molecular biology and genetics, mutations are accidental changes in a genomic sequence of DNA: the DNA sequence of a cell's genome or the DNA or RNA sequence in some viruses. These random sequences can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that, occur during meiosis or DNA replication.
[20] The dimension of which of the following is the same as that of impulse?
A.
Volume
B.
Momentum
C.
Torque
D.
Change in the rate of momentum
Ans:
Momentum
Explanation :
The quantity of impulse is force x time interval. In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter or moving slower, then it would have less momentum.
[21] Which among the following is the fundamental quantity?
A.
Volume
B.
Time
C.
Velocity
D.
Force
Ans:
Time
Explanation :
The fundamental qualities of Physics are the seven basic quantities that can be used to express all other physical quantities. These are as follows: Length: Metre, Heat: Kelvin, Time: second, Luminous Intensity: Candela, Mass: Kilogram, Electric Current: Ampere, and Amount of substance: Moles.
[22] Global warming is expected to result in –
A.
Increase in level of sea
B.
Change in crop pattern
C.
Change in coast line
D.
All of the above
Ans:
All of the above
Explanation :
Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a probable expansion of subtropical deserts.
[23] A transformer works on the principle of –
A.
Self induction
B.
Mutual induction
C.
Generator
D.
Inverter
Ans:
Mutual induction
Explanation :
A transformer is a power converter that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.
[24] Who defined the law of gravitation?
A.
Newton
B.
Archimedes
C.
Galileo
D.
Faraday
Ans:
Newton
Explanation :
Sir Isaac Newton brought out his monograph, titled ‘Philosophiæ Naturalis Principia Mathematica,’ in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. Newton’s law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
[25] Which of the following parts of the sunlight makes the solar cooker hot?
A.
Ultra violet
B.
Red light
C.
Infra red
D.
Cosmic rays
Ans:
Infra red
Explanation :
Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.
Explanation :
Magnetic resonance imaging (MRI), nuclear magnetic resonance imaging (NMRI), or magnetic resonance tomography (MRT) is a medical imaging technique used in radiology to visualize internal structures of the body in detail. MRI makes use of the property of nuclear magnetic resonance (NMR) to image nuclei of atoms inside the body.
[4] For a person having hypermetropia, the near point is –
A.
greater than 25 cm
B.
greater than 50 cm
C.
less than 25 cm
D.
infinity
Ans:
greater than 25 cm
Explanation :
For a hyper-metropic eye, the near points shift away from the eye i.e. farther away from the normal near point (25cm). In a hypermetropic eye, the light is not bent sufficiently so that it focuses at a point behind the retina. Here a person sees well for distance but near vision is difficult and causes strain. Hence hypermetropic people are called long-sighted. To correct the hypermetropic eye, a plus lens is required so that the light can now focus on the retina.
[5] Amount of water vapour in the atmosphere is measured in terms of –
A.
Humidity
B.
Droplets
C.
Smog
D.
All of the above
Ans:
Humidity
Explanation :
Humidity is the amount of water vapor in the air. Water vapor is the has phase of water and is invisible. Humidity indicates the likelihood of precipitation, dew, or fog. Higher humidity reduces the effectiveness of sweating in cooling the body by reducing the rate of evaporation of moisture from the skin.
[6] Name the process of production of energy in the Sun –
A.
Nuclear fission
B.
Radioactivity
C.
Nuclear fusion
D.
Ionization
Ans:
Nuclear fusion
Explanation :
The source of the sun's fuel is hydrogen and helium gases. Through a special chemical reaction, called nuclear fusion, the hydrogen gas is "burned" releasing an enormous amount of energy in the form of light and heat.
[7] The ozone hole that has been detected lies in the atmosphere above –
A.
Arctic Ocean
B.
Antarctica
C.
India
D.
Alaska
Ans:
Antarctica
Explanation :
Ozone layer, that is, the layer of life-protecting ozone found at the top of the stratosphere. Ozone is formed in the earth's stratosphere and is critical to life on earth as we know it. There is compelling scientific evidence that ozone is destroyed in the stratosphere and that some human-released chemicals are speeding up the breakdown of ozone in the atmosphere.
[8] The device used to change the speed of an electric fan is –
A.
Amplifier
B.
Regulator
C.
Switch
D.
Rectifier
Ans:
Regulator
Explanation :
A voltage regulator is designed to automatically maintain a constant voltage level. A voltage regulator maybe a simple "feed-forward" design or may include negative feedback control loops. It may use an electromechanical mechanism, or electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages. Electronic voltage regulators are found in devices such as computer power supplies where they stabilize the DC voltages used by the processor and other elements.
[9] Which one of the following wave-lengths of light is most effective in photosynthesis?
A.
Blue
B.
Green
C.
Orange
D.
Yellow
Ans:
Blue
Explanation :
Photosynthesis, process by which green plants and certain other organisms use the energy of light to convert carbon dioxide and water into the simple sugar glucose. The wavelength most effective in conducting photosynthesis is 420nm. Actually, 420nrn is on the blue side of the spectrum, which makes up between 1 and 10% of the light needed for photosynthesis.
[10] Why is it difficult to breathe at higher altitudes?
A.
Due to low air pressure
B.
Due to low temperature
C.
Due to ozone
D.
Due to high humidity
Ans:
Due to low air pressure
Explanation :
Low air pressure is usually the most significant limiting factor in high mountain regions. The percentage of oxygen in the air at 3.2 km is essentially the same as at sea level (21%). However, the air pressure is 30% lower at the higher altitude due to the fact that the atmosphere is less dense—that is the air molecules are farther apart. At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our vascular systems.
[11] The reason for a swimming pool to appear less deep than the actual depth is –
A.
Refraction
B.
Light scattering
C.
Reflection
D.
Interference
Ans:
Refraction
Explanation :
The apparent depth will look less that its real depth due to the refraction of light. Refraction is the bending of a wave when it enters a medium where it's speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law.
[12] Alternating current is converted into direct current by a –
A.
Transformer
B.
Dynamo
C.
Oscillator
D.
Rectifier
Ans:
Rectifier
Explanation :
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification.
[13] Remote-sensing device has an inbuilt source of –
A.
X-ray
B.
g-ray
C.
Ultraviolet ray
D.
Infrared ray
Ans:
Infrared ray
Explanation :
Infrared imaging is used extensively for military and civilian purposes. Military applications include target acquisition, surveillance, night vision, homing and tracking. Non-military uses include thermal efficiency analysis, environmental monitoring, industrial facility inspections, remote temperature sensing, short-ranged wireless communication, spectroscopy, and weather forecasting.
[14] The atmosphere is heated mainly by –
A.
Insulation
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
Changes in weather involve air movements, formation of clouds, and precipitation. Energy is needed to make all these things happen. That energy comes from the sun. Heat energy enters and moves through the atmosphere in three different ways. One way that heat energy is transferred is radiation. Hot bodies such as the sun radiate their energy mainly in the form of short waves.
[15] The atmospheric layer reflecting radio waves is called –
A.
Ozonosphere
B.
Ionosphere
C.
Stratosphere
D.
Mesosphere
Ans:
Ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere, from about 85 km to 600 km altitude, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth.
[16] 'Cryogenics' is a science dealing with –
A.
high temperatures
B.
low temperatures
C.
friction and wear
D.
growth of crystals
Ans:
low temperatures
Explanation :
Cryogenics is the study of how to get to low temperatures and of how materials behave when they get there. Besides the familiar temperature scales of Fahrenheit and Celsius (Centigrade), cryogenicists use other temperature scales, the Kelvin and Rankine temperature scales. One of the more modern processes being used to treat metals (as well as other materials) is cryogenic tempering.
[17] Heat from the Sun reaches the Earth by –
A.
Reflection
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
The radiation (light, heat, etc.) travels through the intervening 150,000,000 kilometers in 8 minutes. Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. Waves of a massive medium itself, such as water waves or sound waves, are usually not considered to be forms of "radiation" in this sense.
[18] The commonly used thermometric substance is _.
A.
mineral oil
B.
Alcohol
C.
Mercury
D.
Petrol
Ans:
Mercury
Explanation :
Thermometric liquids are used in thermometers to measure temperature. Mercury and alcohol are common thermometric liquids.
[19] Gamma rays can cause –
A.
gene mutation
B.
sneezing
C.
burning
D.
fever
Ans:
gene mutation
Explanation :
In molecular biology and genetics, mutations are accidental changes in a genomic sequence of DNA: the DNA sequence of a cell's genome or the DNA or RNA sequence in some viruses. These random sequences can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that, occur during meiosis or DNA replication.
[20] The dimension of which of the following is the same as that of impulse?
A.
Volume
B.
Momentum
C.
Torque
D.
Change in the rate of momentum
Ans:
Momentum
Explanation :
The quantity of impulse is force x time interval. In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter or moving slower, then it would have less momentum.
[21] Which among the following is the fundamental quantity?
A.
Volume
B.
Time
C.
Velocity
D.
Force
Ans:
Time
Explanation :
The fundamental qualities of Physics are the seven basic quantities that can be used to express all other physical quantities. These are as follows: Length: Metre, Heat: Kelvin, Time: second, Luminous Intensity: Candela, Mass: Kilogram, Electric Current: Ampere, and Amount of substance: Moles.
[22] Global warming is expected to result in –
A.
Increase in level of sea
B.
Change in crop pattern
C.
Change in coast line
D.
All of the above
Ans:
All of the above
Explanation :
Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a probable expansion of subtropical deserts.
[23] A transformer works on the principle of –
A.
Self induction
B.
Mutual induction
C.
Generator
D.
Inverter
Ans:
Mutual induction
Explanation :
A transformer is a power converter that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.
[24] Who defined the law of gravitation?
A.
Newton
B.
Archimedes
C.
Galileo
D.
Faraday
Ans:
Newton
Explanation :
Sir Isaac Newton brought out his monograph, titled ‘Philosophiæ Naturalis Principia Mathematica,’ in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. Newton’s law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
[25] Which of the following parts of the sunlight makes the solar cooker hot?
A.
Ultra violet
B.
Red light
C.
Infra red
D.
Cosmic rays
Ans:
Infra red
Explanation :
Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.
Explanation :
Humidity is the amount of water vapor in the air. Water vapor is the has phase of water and is invisible. Humidity indicates the likelihood of precipitation, dew, or fog. Higher humidity reduces the effectiveness of sweating in cooling the body by reducing the rate of evaporation of moisture from the skin.
[6] Name the process of production of energy in the Sun –
A.
Nuclear fission
B.
Radioactivity
C.
Nuclear fusion
D.
Ionization
Ans:
Nuclear fusion
Explanation :
The source of the sun's fuel is hydrogen and helium gases. Through a special chemical reaction, called nuclear fusion, the hydrogen gas is "burned" releasing an enormous amount of energy in the form of light and heat.
[7] The ozone hole that has been detected lies in the atmosphere above –
A.
Arctic Ocean
B.
Antarctica
C.
India
D.
Alaska
Ans:
Antarctica
Explanation :
Ozone layer, that is, the layer of life-protecting ozone found at the top of the stratosphere. Ozone is formed in the earth's stratosphere and is critical to life on earth as we know it. There is compelling scientific evidence that ozone is destroyed in the stratosphere and that some human-released chemicals are speeding up the breakdown of ozone in the atmosphere.
[8] The device used to change the speed of an electric fan is –
A.
Amplifier
B.
Regulator
C.
Switch
D.
Rectifier
Ans:
Regulator
Explanation :
A voltage regulator is designed to automatically maintain a constant voltage level. A voltage regulator maybe a simple "feed-forward" design or may include negative feedback control loops. It may use an electromechanical mechanism, or electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages. Electronic voltage regulators are found in devices such as computer power supplies where they stabilize the DC voltages used by the processor and other elements.
[9] Which one of the following wave-lengths of light is most effective in photosynthesis?
A.
Blue
B.
Green
C.
Orange
D.
Yellow
Ans:
Blue
Explanation :
Photosynthesis, process by which green plants and certain other organisms use the energy of light to convert carbon dioxide and water into the simple sugar glucose. The wavelength most effective in conducting photosynthesis is 420nm. Actually, 420nrn is on the blue side of the spectrum, which makes up between 1 and 10% of the light needed for photosynthesis.
[10] Why is it difficult to breathe at higher altitudes?
A.
Due to low air pressure
B.
Due to low temperature
C.
Due to ozone
D.
Due to high humidity
Ans:
Due to low air pressure
Explanation :
Low air pressure is usually the most significant limiting factor in high mountain regions. The percentage of oxygen in the air at 3.2 km is essentially the same as at sea level (21%). However, the air pressure is 30% lower at the higher altitude due to the fact that the atmosphere is less dense—that is the air molecules are farther apart. At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our vascular systems.
[11] The reason for a swimming pool to appear less deep than the actual depth is –
A.
Refraction
B.
Light scattering
C.
Reflection
D.
Interference
Ans:
Refraction
Explanation :
The apparent depth will look less that its real depth due to the refraction of light. Refraction is the bending of a wave when it enters a medium where it's speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law.
[12] Alternating current is converted into direct current by a –
A.
Transformer
B.
Dynamo
C.
Oscillator
D.
Rectifier
Ans:
Rectifier
Explanation :
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification.
[13] Remote-sensing device has an inbuilt source of –
A.
X-ray
B.
g-ray
C.
Ultraviolet ray
D.
Infrared ray
Ans:
Infrared ray
Explanation :
Infrared imaging is used extensively for military and civilian purposes. Military applications include target acquisition, surveillance, night vision, homing and tracking. Non-military uses include thermal efficiency analysis, environmental monitoring, industrial facility inspections, remote temperature sensing, short-ranged wireless communication, spectroscopy, and weather forecasting.
[14] The atmosphere is heated mainly by –
A.
Insulation
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
Changes in weather involve air movements, formation of clouds, and precipitation. Energy is needed to make all these things happen. That energy comes from the sun. Heat energy enters and moves through the atmosphere in three different ways. One way that heat energy is transferred is radiation. Hot bodies such as the sun radiate their energy mainly in the form of short waves.
[15] The atmospheric layer reflecting radio waves is called –
A.
Ozonosphere
B.
Ionosphere
C.
Stratosphere
D.
Mesosphere
Ans:
Ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere, from about 85 km to 600 km altitude, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth.
[16] 'Cryogenics' is a science dealing with –
A.
high temperatures
B.
low temperatures
C.
friction and wear
D.
growth of crystals
Ans:
low temperatures
Explanation :
Cryogenics is the study of how to get to low temperatures and of how materials behave when they get there. Besides the familiar temperature scales of Fahrenheit and Celsius (Centigrade), cryogenicists use other temperature scales, the Kelvin and Rankine temperature scales. One of the more modern processes being used to treat metals (as well as other materials) is cryogenic tempering.
[17] Heat from the Sun reaches the Earth by –
A.
Reflection
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
The radiation (light, heat, etc.) travels through the intervening 150,000,000 kilometers in 8 minutes. Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. Waves of a massive medium itself, such as water waves or sound waves, are usually not considered to be forms of "radiation" in this sense.
[18] The commonly used thermometric substance is _.
A.
mineral oil
B.
Alcohol
C.
Mercury
D.
Petrol
Ans:
Mercury
Explanation :
Thermometric liquids are used in thermometers to measure temperature. Mercury and alcohol are common thermometric liquids.
[19] Gamma rays can cause –
A.
gene mutation
B.
sneezing
C.
burning
D.
fever
Ans:
gene mutation
Explanation :
In molecular biology and genetics, mutations are accidental changes in a genomic sequence of DNA: the DNA sequence of a cell's genome or the DNA or RNA sequence in some viruses. These random sequences can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that, occur during meiosis or DNA replication.
[20] The dimension of which of the following is the same as that of impulse?
A.
Volume
B.
Momentum
C.
Torque
D.
Change in the rate of momentum
Ans:
Momentum
Explanation :
The quantity of impulse is force x time interval. In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter or moving slower, then it would have less momentum.
[21] Which among the following is the fundamental quantity?
A.
Volume
B.
Time
C.
Velocity
D.
Force
Ans:
Time
Explanation :
The fundamental qualities of Physics are the seven basic quantities that can be used to express all other physical quantities. These are as follows: Length: Metre, Heat: Kelvin, Time: second, Luminous Intensity: Candela, Mass: Kilogram, Electric Current: Ampere, and Amount of substance: Moles.
[22] Global warming is expected to result in –
A.
Increase in level of sea
B.
Change in crop pattern
C.
Change in coast line
D.
All of the above
Ans:
All of the above
Explanation :
Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a probable expansion of subtropical deserts.
[23] A transformer works on the principle of –
A.
Self induction
B.
Mutual induction
C.
Generator
D.
Inverter
Ans:
Mutual induction
Explanation :
A transformer is a power converter that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.
[24] Who defined the law of gravitation?
A.
Newton
B.
Archimedes
C.
Galileo
D.
Faraday
Ans:
Newton
Explanation :
Sir Isaac Newton brought out his monograph, titled ‘Philosophiæ Naturalis Principia Mathematica,’ in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. Newton’s law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
[25] Which of the following parts of the sunlight makes the solar cooker hot?
A.
Ultra violet
B.
Red light
C.
Infra red
D.
Cosmic rays
Ans:
Infra red
Explanation :
Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.
Explanation :
Ozone layer, that is, the layer of life-protecting ozone found at the top of the stratosphere. Ozone is formed in the earth's stratosphere and is critical to life on earth as we know it. There is compelling scientific evidence that ozone is destroyed in the stratosphere and that some human-released chemicals are speeding up the breakdown of ozone in the atmosphere.
[8] The device used to change the speed of an electric fan is –
A.
Amplifier
B.
Regulator
C.
Switch
D.
Rectifier
Ans:
Regulator
Explanation :
A voltage regulator is designed to automatically maintain a constant voltage level. A voltage regulator maybe a simple "feed-forward" design or may include negative feedback control loops. It may use an electromechanical mechanism, or electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages. Electronic voltage regulators are found in devices such as computer power supplies where they stabilize the DC voltages used by the processor and other elements.
[9] Which one of the following wave-lengths of light is most effective in photosynthesis?
A.
Blue
B.
Green
C.
Orange
D.
Yellow
Ans:
Blue
Explanation :
Photosynthesis, process by which green plants and certain other organisms use the energy of light to convert carbon dioxide and water into the simple sugar glucose. The wavelength most effective in conducting photosynthesis is 420nm. Actually, 420nrn is on the blue side of the spectrum, which makes up between 1 and 10% of the light needed for photosynthesis.
[10] Why is it difficult to breathe at higher altitudes?
A.
Due to low air pressure
B.
Due to low temperature
C.
Due to ozone
D.
Due to high humidity
Ans:
Due to low air pressure
Explanation :
Low air pressure is usually the most significant limiting factor in high mountain regions. The percentage of oxygen in the air at 3.2 km is essentially the same as at sea level (21%). However, the air pressure is 30% lower at the higher altitude due to the fact that the atmosphere is less dense—that is the air molecules are farther apart. At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our vascular systems.
[11] The reason for a swimming pool to appear less deep than the actual depth is –
A.
Refraction
B.
Light scattering
C.
Reflection
D.
Interference
Ans:
Refraction
Explanation :
The apparent depth will look less that its real depth due to the refraction of light. Refraction is the bending of a wave when it enters a medium where it's speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law.
[12] Alternating current is converted into direct current by a –
A.
Transformer
B.
Dynamo
C.
Oscillator
D.
Rectifier
Ans:
Rectifier
Explanation :
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification.
[13] Remote-sensing device has an inbuilt source of –
A.
X-ray
B.
g-ray
C.
Ultraviolet ray
D.
Infrared ray
Ans:
Infrared ray
Explanation :
Infrared imaging is used extensively for military and civilian purposes. Military applications include target acquisition, surveillance, night vision, homing and tracking. Non-military uses include thermal efficiency analysis, environmental monitoring, industrial facility inspections, remote temperature sensing, short-ranged wireless communication, spectroscopy, and weather forecasting.
[14] The atmosphere is heated mainly by –
A.
Insulation
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
Changes in weather involve air movements, formation of clouds, and precipitation. Energy is needed to make all these things happen. That energy comes from the sun. Heat energy enters and moves through the atmosphere in three different ways. One way that heat energy is transferred is radiation. Hot bodies such as the sun radiate their energy mainly in the form of short waves.
[15] The atmospheric layer reflecting radio waves is called –
A.
Ozonosphere
B.
Ionosphere
C.
Stratosphere
D.
Mesosphere
Ans:
Ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere, from about 85 km to 600 km altitude, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth.
[16] 'Cryogenics' is a science dealing with –
A.
high temperatures
B.
low temperatures
C.
friction and wear
D.
growth of crystals
Ans:
low temperatures
Explanation :
Cryogenics is the study of how to get to low temperatures and of how materials behave when they get there. Besides the familiar temperature scales of Fahrenheit and Celsius (Centigrade), cryogenicists use other temperature scales, the Kelvin and Rankine temperature scales. One of the more modern processes being used to treat metals (as well as other materials) is cryogenic tempering.
[17] Heat from the Sun reaches the Earth by –
A.
Reflection
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
The radiation (light, heat, etc.) travels through the intervening 150,000,000 kilometers in 8 minutes. Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. Waves of a massive medium itself, such as water waves or sound waves, are usually not considered to be forms of "radiation" in this sense.
[18] The commonly used thermometric substance is _.
A.
mineral oil
B.
Alcohol
C.
Mercury
D.
Petrol
Ans:
Mercury
Explanation :
Thermometric liquids are used in thermometers to measure temperature. Mercury and alcohol are common thermometric liquids.
[19] Gamma rays can cause –
A.
gene mutation
B.
sneezing
C.
burning
D.
fever
Ans:
gene mutation
Explanation :
In molecular biology and genetics, mutations are accidental changes in a genomic sequence of DNA: the DNA sequence of a cell's genome or the DNA or RNA sequence in some viruses. These random sequences can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that, occur during meiosis or DNA replication.
[20] The dimension of which of the following is the same as that of impulse?
A.
Volume
B.
Momentum
C.
Torque
D.
Change in the rate of momentum
Ans:
Momentum
Explanation :
The quantity of impulse is force x time interval. In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter or moving slower, then it would have less momentum.
[21] Which among the following is the fundamental quantity?
A.
Volume
B.
Time
C.
Velocity
D.
Force
Ans:
Time
Explanation :
The fundamental qualities of Physics are the seven basic quantities that can be used to express all other physical quantities. These are as follows: Length: Metre, Heat: Kelvin, Time: second, Luminous Intensity: Candela, Mass: Kilogram, Electric Current: Ampere, and Amount of substance: Moles.
[22] Global warming is expected to result in –
A.
Increase in level of sea
B.
Change in crop pattern
C.
Change in coast line
D.
All of the above
Ans:
All of the above
Explanation :
Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a probable expansion of subtropical deserts.
[23] A transformer works on the principle of –
A.
Self induction
B.
Mutual induction
C.
Generator
D.
Inverter
Ans:
Mutual induction
Explanation :
A transformer is a power converter that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.
[24] Who defined the law of gravitation?
A.
Newton
B.
Archimedes
C.
Galileo
D.
Faraday
Ans:
Newton
Explanation :
Sir Isaac Newton brought out his monograph, titled ‘Philosophiæ Naturalis Principia Mathematica,’ in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. Newton’s law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
[25] Which of the following parts of the sunlight makes the solar cooker hot?
A.
Ultra violet
B.
Red light
C.
Infra red
D.
Cosmic rays
Ans:
Infra red
Explanation :
Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.
Explanation :
Photosynthesis, process by which green plants and certain other organisms use the energy of light to convert carbon dioxide and water into the simple sugar glucose. The wavelength most effective in conducting photosynthesis is 420nm. Actually, 420nrn is on the blue side of the spectrum, which makes up between 1 and 10% of the light needed for photosynthesis.
[10] Why is it difficult to breathe at higher altitudes?
A.
Due to low air pressure
B.
Due to low temperature
C.
Due to ozone
D.
Due to high humidity
Ans:
Due to low air pressure
Explanation :
Low air pressure is usually the most significant limiting factor in high mountain regions. The percentage of oxygen in the air at 3.2 km is essentially the same as at sea level (21%). However, the air pressure is 30% lower at the higher altitude due to the fact that the atmosphere is less dense—that is the air molecules are farther apart. At high altitudes, the lower air pressure makes it more difficult for oxygen to enter our vascular systems.
[11] The reason for a swimming pool to appear less deep than the actual depth is –
A.
Refraction
B.
Light scattering
C.
Reflection
D.
Interference
Ans:
Refraction
Explanation :
The apparent depth will look less that its real depth due to the refraction of light. Refraction is the bending of a wave when it enters a medium where it's speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law.
[12] Alternating current is converted into direct current by a –
A.
Transformer
B.
Dynamo
C.
Oscillator
D.
Rectifier
Ans:
Rectifier
Explanation :
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification.
[13] Remote-sensing device has an inbuilt source of –
A.
X-ray
B.
g-ray
C.
Ultraviolet ray
D.
Infrared ray
Ans:
Infrared ray
Explanation :
Infrared imaging is used extensively for military and civilian purposes. Military applications include target acquisition, surveillance, night vision, homing and tracking. Non-military uses include thermal efficiency analysis, environmental monitoring, industrial facility inspections, remote temperature sensing, short-ranged wireless communication, spectroscopy, and weather forecasting.
[14] The atmosphere is heated mainly by –
A.
Insulation
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
Changes in weather involve air movements, formation of clouds, and precipitation. Energy is needed to make all these things happen. That energy comes from the sun. Heat energy enters and moves through the atmosphere in three different ways. One way that heat energy is transferred is radiation. Hot bodies such as the sun radiate their energy mainly in the form of short waves.
[15] The atmospheric layer reflecting radio waves is called –
A.
Ozonosphere
B.
Ionosphere
C.
Stratosphere
D.
Mesosphere
Ans:
Ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere, from about 85 km to 600 km altitude, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth.
[16] 'Cryogenics' is a science dealing with –
A.
high temperatures
B.
low temperatures
C.
friction and wear
D.
growth of crystals
Ans:
low temperatures
Explanation :
Cryogenics is the study of how to get to low temperatures and of how materials behave when they get there. Besides the familiar temperature scales of Fahrenheit and Celsius (Centigrade), cryogenicists use other temperature scales, the Kelvin and Rankine temperature scales. One of the more modern processes being used to treat metals (as well as other materials) is cryogenic tempering.
[17] Heat from the Sun reaches the Earth by –
A.
Reflection
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
The radiation (light, heat, etc.) travels through the intervening 150,000,000 kilometers in 8 minutes. Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. Waves of a massive medium itself, such as water waves or sound waves, are usually not considered to be forms of "radiation" in this sense.
[18] The commonly used thermometric substance is _.
A.
mineral oil
B.
Alcohol
C.
Mercury
D.
Petrol
Ans:
Mercury
Explanation :
Thermometric liquids are used in thermometers to measure temperature. Mercury and alcohol are common thermometric liquids.
[19] Gamma rays can cause –
A.
gene mutation
B.
sneezing
C.
burning
D.
fever
Ans:
gene mutation
Explanation :
In molecular biology and genetics, mutations are accidental changes in a genomic sequence of DNA: the DNA sequence of a cell's genome or the DNA or RNA sequence in some viruses. These random sequences can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that, occur during meiosis or DNA replication.
[20] The dimension of which of the following is the same as that of impulse?
A.
Volume
B.
Momentum
C.
Torque
D.
Change in the rate of momentum
Ans:
Momentum
Explanation :
The quantity of impulse is force x time interval. In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter or moving slower, then it would have less momentum.
[21] Which among the following is the fundamental quantity?
A.
Volume
B.
Time
C.
Velocity
D.
Force
Ans:
Time
Explanation :
The fundamental qualities of Physics are the seven basic quantities that can be used to express all other physical quantities. These are as follows: Length: Metre, Heat: Kelvin, Time: second, Luminous Intensity: Candela, Mass: Kilogram, Electric Current: Ampere, and Amount of substance: Moles.
[22] Global warming is expected to result in –
A.
Increase in level of sea
B.
Change in crop pattern
C.
Change in coast line
D.
All of the above
Ans:
All of the above
Explanation :
Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a probable expansion of subtropical deserts.
[23] A transformer works on the principle of –
A.
Self induction
B.
Mutual induction
C.
Generator
D.
Inverter
Ans:
Mutual induction
Explanation :
A transformer is a power converter that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.
[24] Who defined the law of gravitation?
A.
Newton
B.
Archimedes
C.
Galileo
D.
Faraday
Ans:
Newton
Explanation :
Sir Isaac Newton brought out his monograph, titled ‘Philosophiæ Naturalis Principia Mathematica,’ in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. Newton’s law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
[25] Which of the following parts of the sunlight makes the solar cooker hot?
A.
Ultra violet
B.
Red light
C.
Infra red
D.
Cosmic rays
Ans:
Infra red
Explanation :
Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.
Explanation :
The apparent depth will look less that its real depth due to the refraction of light. Refraction is the bending of a wave when it enters a medium where it's speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law.
[12] Alternating current is converted into direct current by a –
A.
Transformer
B.
Dynamo
C.
Oscillator
D.
Rectifier
Ans:
Rectifier
Explanation :
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification.
[13] Remote-sensing device has an inbuilt source of –
A.
X-ray
B.
g-ray
C.
Ultraviolet ray
D.
Infrared ray
Ans:
Infrared ray
Explanation :
Infrared imaging is used extensively for military and civilian purposes. Military applications include target acquisition, surveillance, night vision, homing and tracking. Non-military uses include thermal efficiency analysis, environmental monitoring, industrial facility inspections, remote temperature sensing, short-ranged wireless communication, spectroscopy, and weather forecasting.
[14] The atmosphere is heated mainly by –
A.
Insulation
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
Changes in weather involve air movements, formation of clouds, and precipitation. Energy is needed to make all these things happen. That energy comes from the sun. Heat energy enters and moves through the atmosphere in three different ways. One way that heat energy is transferred is radiation. Hot bodies such as the sun radiate their energy mainly in the form of short waves.
[15] The atmospheric layer reflecting radio waves is called –
A.
Ozonosphere
B.
Ionosphere
C.
Stratosphere
D.
Mesosphere
Ans:
Ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere, from about 85 km to 600 km altitude, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth.
[16] 'Cryogenics' is a science dealing with –
A.
high temperatures
B.
low temperatures
C.
friction and wear
D.
growth of crystals
Ans:
low temperatures
Explanation :
Cryogenics is the study of how to get to low temperatures and of how materials behave when they get there. Besides the familiar temperature scales of Fahrenheit and Celsius (Centigrade), cryogenicists use other temperature scales, the Kelvin and Rankine temperature scales. One of the more modern processes being used to treat metals (as well as other materials) is cryogenic tempering.
[17] Heat from the Sun reaches the Earth by –
A.
Reflection
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
The radiation (light, heat, etc.) travels through the intervening 150,000,000 kilometers in 8 minutes. Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. Waves of a massive medium itself, such as water waves or sound waves, are usually not considered to be forms of "radiation" in this sense.
[18] The commonly used thermometric substance is _.
A.
mineral oil
B.
Alcohol
C.
Mercury
D.
Petrol
Ans:
Mercury
Explanation :
Thermometric liquids are used in thermometers to measure temperature. Mercury and alcohol are common thermometric liquids.
[19] Gamma rays can cause –
A.
gene mutation
B.
sneezing
C.
burning
D.
fever
Ans:
gene mutation
Explanation :
In molecular biology and genetics, mutations are accidental changes in a genomic sequence of DNA: the DNA sequence of a cell's genome or the DNA or RNA sequence in some viruses. These random sequences can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that, occur during meiosis or DNA replication.
[20] The dimension of which of the following is the same as that of impulse?
A.
Volume
B.
Momentum
C.
Torque
D.
Change in the rate of momentum
Ans:
Momentum
Explanation :
The quantity of impulse is force x time interval. In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter or moving slower, then it would have less momentum.
[21] Which among the following is the fundamental quantity?
A.
Volume
B.
Time
C.
Velocity
D.
Force
Ans:
Time
Explanation :
The fundamental qualities of Physics are the seven basic quantities that can be used to express all other physical quantities. These are as follows: Length: Metre, Heat: Kelvin, Time: second, Luminous Intensity: Candela, Mass: Kilogram, Electric Current: Ampere, and Amount of substance: Moles.
[22] Global warming is expected to result in –
A.
Increase in level of sea
B.
Change in crop pattern
C.
Change in coast line
D.
All of the above
Ans:
All of the above
Explanation :
Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a probable expansion of subtropical deserts.
[23] A transformer works on the principle of –
A.
Self induction
B.
Mutual induction
C.
Generator
D.
Inverter
Ans:
Mutual induction
Explanation :
A transformer is a power converter that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.
[24] Who defined the law of gravitation?
A.
Newton
B.
Archimedes
C.
Galileo
D.
Faraday
Ans:
Newton
Explanation :
Sir Isaac Newton brought out his monograph, titled ‘Philosophiæ Naturalis Principia Mathematica,’ in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. Newton’s law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
[25] Which of the following parts of the sunlight makes the solar cooker hot?
A.
Ultra violet
B.
Red light
C.
Infra red
D.
Cosmic rays
Ans:
Infra red
Explanation :
Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.
Explanation :
Infrared imaging is used extensively for military and civilian purposes. Military applications include target acquisition, surveillance, night vision, homing and tracking. Non-military uses include thermal efficiency analysis, environmental monitoring, industrial facility inspections, remote temperature sensing, short-ranged wireless communication, spectroscopy, and weather forecasting.
[14] The atmosphere is heated mainly by –
A.
Insulation
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
Changes in weather involve air movements, formation of clouds, and precipitation. Energy is needed to make all these things happen. That energy comes from the sun. Heat energy enters and moves through the atmosphere in three different ways. One way that heat energy is transferred is radiation. Hot bodies such as the sun radiate their energy mainly in the form of short waves.
[15] The atmospheric layer reflecting radio waves is called –
A.
Ozonosphere
B.
Ionosphere
C.
Stratosphere
D.
Mesosphere
Ans:
Ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere, from about 85 km to 600 km altitude, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth.
[16] 'Cryogenics' is a science dealing with –
A.
high temperatures
B.
low temperatures
C.
friction and wear
D.
growth of crystals
Ans:
low temperatures
Explanation :
Cryogenics is the study of how to get to low temperatures and of how materials behave when they get there. Besides the familiar temperature scales of Fahrenheit and Celsius (Centigrade), cryogenicists use other temperature scales, the Kelvin and Rankine temperature scales. One of the more modern processes being used to treat metals (as well as other materials) is cryogenic tempering.
[17] Heat from the Sun reaches the Earth by –
A.
Reflection
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
The radiation (light, heat, etc.) travels through the intervening 150,000,000 kilometers in 8 minutes. Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. Waves of a massive medium itself, such as water waves or sound waves, are usually not considered to be forms of "radiation" in this sense.
[18] The commonly used thermometric substance is _.
A.
mineral oil
B.
Alcohol
C.
Mercury
D.
Petrol
Ans:
Mercury
Explanation :
Thermometric liquids are used in thermometers to measure temperature. Mercury and alcohol are common thermometric liquids.
[19] Gamma rays can cause –
A.
gene mutation
B.
sneezing
C.
burning
D.
fever
Ans:
gene mutation
Explanation :
In molecular biology and genetics, mutations are accidental changes in a genomic sequence of DNA: the DNA sequence of a cell's genome or the DNA or RNA sequence in some viruses. These random sequences can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that, occur during meiosis or DNA replication.
[20] The dimension of which of the following is the same as that of impulse?
A.
Volume
B.
Momentum
C.
Torque
D.
Change in the rate of momentum
Ans:
Momentum
Explanation :
The quantity of impulse is force x time interval. In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter or moving slower, then it would have less momentum.
[21] Which among the following is the fundamental quantity?
A.
Volume
B.
Time
C.
Velocity
D.
Force
Ans:
Time
Explanation :
The fundamental qualities of Physics are the seven basic quantities that can be used to express all other physical quantities. These are as follows: Length: Metre, Heat: Kelvin, Time: second, Luminous Intensity: Candela, Mass: Kilogram, Electric Current: Ampere, and Amount of substance: Moles.
[22] Global warming is expected to result in –
A.
Increase in level of sea
B.
Change in crop pattern
C.
Change in coast line
D.
All of the above
Ans:
All of the above
Explanation :
Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a probable expansion of subtropical deserts.
[23] A transformer works on the principle of –
A.
Self induction
B.
Mutual induction
C.
Generator
D.
Inverter
Ans:
Mutual induction
Explanation :
A transformer is a power converter that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.
[24] Who defined the law of gravitation?
A.
Newton
B.
Archimedes
C.
Galileo
D.
Faraday
Ans:
Newton
Explanation :
Sir Isaac Newton brought out his monograph, titled ‘Philosophiæ Naturalis Principia Mathematica,’ in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. Newton’s law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
[25] Which of the following parts of the sunlight makes the solar cooker hot?
A.
Ultra violet
B.
Red light
C.
Infra red
D.
Cosmic rays
Ans:
Infra red
Explanation :
Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.
Explanation :
The ionosphere is a part of the upper atmosphere, from about 85 km to 600 km altitude, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth.
[16] 'Cryogenics' is a science dealing with –
A.
high temperatures
B.
low temperatures
C.
friction and wear
D.
growth of crystals
Ans:
low temperatures
Explanation :
Cryogenics is the study of how to get to low temperatures and of how materials behave when they get there. Besides the familiar temperature scales of Fahrenheit and Celsius (Centigrade), cryogenicists use other temperature scales, the Kelvin and Rankine temperature scales. One of the more modern processes being used to treat metals (as well as other materials) is cryogenic tempering.
[17] Heat from the Sun reaches the Earth by –
A.
Reflection
B.
Conduction
C.
Radiation
D.
Convection
Ans:
Radiation
Explanation :
The radiation (light, heat, etc.) travels through the intervening 150,000,000 kilometers in 8 minutes. Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. Waves of a massive medium itself, such as water waves or sound waves, are usually not considered to be forms of "radiation" in this sense.
[18] The commonly used thermometric substance is _.
A.
mineral oil
B.
Alcohol
C.
Mercury
D.
Petrol
Ans:
Mercury
Explanation :
Thermometric liquids are used in thermometers to measure temperature. Mercury and alcohol are common thermometric liquids.
[19] Gamma rays can cause –
A.
gene mutation
B.
sneezing
C.
burning
D.
fever
Ans:
gene mutation
Explanation :
In molecular biology and genetics, mutations are accidental changes in a genomic sequence of DNA: the DNA sequence of a cell's genome or the DNA or RNA sequence in some viruses. These random sequences can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that, occur during meiosis or DNA replication.
[20] The dimension of which of the following is the same as that of impulse?
A.
Volume
B.
Momentum
C.
Torque
D.
Change in the rate of momentum
Ans:
Momentum
Explanation :
The quantity of impulse is force x time interval. In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter or moving slower, then it would have less momentum.
[21] Which among the following is the fundamental quantity?
A.
Volume
B.
Time
C.
Velocity
D.
Force
Ans:
Time
Explanation :
The fundamental qualities of Physics are the seven basic quantities that can be used to express all other physical quantities. These are as follows: Length: Metre, Heat: Kelvin, Time: second, Luminous Intensity: Candela, Mass: Kilogram, Electric Current: Ampere, and Amount of substance: Moles.
[22] Global warming is expected to result in –
A.
Increase in level of sea
B.
Change in crop pattern
C.
Change in coast line
D.
All of the above
Ans:
All of the above
Explanation :
Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a probable expansion of subtropical deserts.
[23] A transformer works on the principle of –
A.
Self induction
B.
Mutual induction
C.
Generator
D.
Inverter
Ans:
Mutual induction
Explanation :
A transformer is a power converter that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.
[24] Who defined the law of gravitation?
A.
Newton
B.
Archimedes
C.
Galileo
D.
Faraday
Ans:
Newton
Explanation :
Sir Isaac Newton brought out his monograph, titled ‘Philosophiæ Naturalis Principia Mathematica,’ in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. Newton’s law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
[25] Which of the following parts of the sunlight makes the solar cooker hot?
A.
Ultra violet
B.
Red light
C.
Infra red
D.
Cosmic rays
Ans:
Infra red
Explanation :
Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.
Explanation :
The radiation (light, heat, etc.) travels through the intervening 150,000,000 kilometers in 8 minutes. Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. Waves of a massive medium itself, such as water waves or sound waves, are usually not considered to be forms of "radiation" in this sense.
[18] The commonly used thermometric substance is _.
A.
mineral oil
B.
Alcohol
C.
Mercury
D.
Petrol
Ans:
Mercury
Explanation :
Thermometric liquids are used in thermometers to measure temperature. Mercury and alcohol are common thermometric liquids.
[19] Gamma rays can cause –
A.
gene mutation
B.
sneezing
C.
burning
D.
fever
Ans:
gene mutation
Explanation :
In molecular biology and genetics, mutations are accidental changes in a genomic sequence of DNA: the DNA sequence of a cell's genome or the DNA or RNA sequence in some viruses. These random sequences can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that, occur during meiosis or DNA replication.
[20] The dimension of which of the following is the same as that of impulse?
A.
Volume
B.
Momentum
C.
Torque
D.
Change in the rate of momentum
Ans:
Momentum
Explanation :
The quantity of impulse is force x time interval. In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter or moving slower, then it would have less momentum.
[21] Which among the following is the fundamental quantity?
A.
Volume
B.
Time
C.
Velocity
D.
Force
Ans:
Time
Explanation :
The fundamental qualities of Physics are the seven basic quantities that can be used to express all other physical quantities. These are as follows: Length: Metre, Heat: Kelvin, Time: second, Luminous Intensity: Candela, Mass: Kilogram, Electric Current: Ampere, and Amount of substance: Moles.
[22] Global warming is expected to result in –
A.
Increase in level of sea
B.
Change in crop pattern
C.
Change in coast line
D.
All of the above
Ans:
All of the above
Explanation :
Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a probable expansion of subtropical deserts.
[23] A transformer works on the principle of –
A.
Self induction
B.
Mutual induction
C.
Generator
D.
Inverter
Ans:
Mutual induction
Explanation :
A transformer is a power converter that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.
[24] Who defined the law of gravitation?
A.
Newton
B.
Archimedes
C.
Galileo
D.
Faraday
Ans:
Newton
Explanation :
Sir Isaac Newton brought out his monograph, titled ‘Philosophiæ Naturalis Principia Mathematica,’ in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. Newton’s law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
[25] Which of the following parts of the sunlight makes the solar cooker hot?
A.
Ultra violet
B.
Red light
C.
Infra red
D.
Cosmic rays
Ans:
Infra red
Explanation :
Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.
Explanation :
In molecular biology and genetics, mutations are accidental changes in a genomic sequence of DNA: the DNA sequence of a cell's genome or the DNA or RNA sequence in some viruses. These random sequences can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that, occur during meiosis or DNA replication.
[20] The dimension of which of the following is the same as that of impulse?
A.
Volume
B.
Momentum
C.
Torque
D.
Change in the rate of momentum
Ans:
Momentum
Explanation :
The quantity of impulse is force x time interval. In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter or moving slower, then it would have less momentum.
[21] Which among the following is the fundamental quantity?
A.
Volume
B.
Time
C.
Velocity
D.
Force
Ans:
Time
Explanation :
The fundamental qualities of Physics are the seven basic quantities that can be used to express all other physical quantities. These are as follows: Length: Metre, Heat: Kelvin, Time: second, Luminous Intensity: Candela, Mass: Kilogram, Electric Current: Ampere, and Amount of substance: Moles.
[22] Global warming is expected to result in –
A.
Increase in level of sea
B.
Change in crop pattern
C.
Change in coast line
D.
All of the above
Ans:
All of the above
Explanation :
Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a probable expansion of subtropical deserts.
[23] A transformer works on the principle of –
A.
Self induction
B.
Mutual induction
C.
Generator
D.
Inverter
Ans:
Mutual induction
Explanation :
A transformer is a power converter that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.
[24] Who defined the law of gravitation?
A.
Newton
B.
Archimedes
C.
Galileo
D.
Faraday
Ans:
Newton
Explanation :
Sir Isaac Newton brought out his monograph, titled ‘Philosophiæ Naturalis Principia Mathematica,’ in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. Newton’s law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
[25] Which of the following parts of the sunlight makes the solar cooker hot?
A.
Ultra violet
B.
Red light
C.
Infra red
D.
Cosmic rays
Ans:
Infra red
Explanation :
Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.
Explanation :
The fundamental qualities of Physics are the seven basic quantities that can be used to express all other physical quantities. These are as follows: Length: Metre, Heat: Kelvin, Time: second, Luminous Intensity: Candela, Mass: Kilogram, Electric Current: Ampere, and Amount of substance: Moles.
[22] Global warming is expected to result in –
A.
Increase in level of sea
B.
Change in crop pattern
C.
Change in coast line
D.
All of the above
Ans:
All of the above
Explanation :
Global warming is the rise in the average temperature of Earth's atmosphere and oceans since the late 19th century and its projected continuation. Since the early 20th century, Earth's mean surface temperature has increased by about 0.8 °C (1.4 °F), with about two-thirds of the increase occurring since 1980. The effects of an increase in global temperature include a rise in sea levels and a change in the amount and pattern of precipitation, as well a probable expansion of subtropical deserts.
[23] A transformer works on the principle of –
A.
Self induction
B.
Mutual induction
C.
Generator
D.
Inverter
Ans:
Mutual induction
Explanation :
A transformer is a power converter that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.
[24] Who defined the law of gravitation?
A.
Newton
B.
Archimedes
C.
Galileo
D.
Faraday
Ans:
Newton
Explanation :
Sir Isaac Newton brought out his monograph, titled ‘Philosophiæ Naturalis Principia Mathematica,’ in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. Newton’s law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
[25] Which of the following parts of the sunlight makes the solar cooker hot?
A.
Ultra violet
B.
Red light
C.
Infra red
D.
Cosmic rays
Ans:
Infra red
Explanation :
Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.
Explanation :
A transformer is a power converter that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.
[24] Who defined the law of gravitation?
A.
Newton
B.
Archimedes
C.
Galileo
D.
Faraday
Ans:
Newton
Explanation :
Sir Isaac Newton brought out his monograph, titled ‘Philosophiæ Naturalis Principia Mathematica,’ in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. Newton’s law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
[25] Which of the following parts of the sunlight makes the solar cooker hot?
A.
Ultra violet
B.
Red light
C.
Infra red
D.
Cosmic rays
Ans:
Infra red
Explanation :
Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.
Explanation :
Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which uses the energy of direct sunlight to heat food or drink to cook it or sterilize it. The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.