[1] The device which converts AC to DC is –
A.
Oscillator
B.
Amplifier
C.
Rectifier
D.
None of these
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. Physically, rectifiers take a number of forms, including vacuum tube diodes, mercury-arc valves, solid- state diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches. Rectifiers have many uses, but are often found serving as components of DC power supplies and high-voltage direct current power transmission systems. Rectification may serve in roles other than to generate direct current for use as a source of power. As noted, detectors of radio signals serve as rectifiers.
[2] What is the minimum escape velocity of rocket to be launched into space?
A.
5 Km/Sec.
B.
6 Km/Sec.
C.
11 Km/Sec.
D.
15 Km/Sec.
Ans:
11 Km/Sec.
Explanation :
On the surface of the Earth, the escape velocity is about 11.2 kilometers per second (~6.96 mi/s), which is approximately 34 times the speed of sound (Mach 34) and several times the muzzle velocity of a rifle bullet (up to 1.7 km/s). However, at 9,000 km altitude in “space”, it is slightly less than 7.1 km/s. In physics, escape velocity is the speed at which the kinetic energy plus the gravitational potential energy of an object is zero. It is the speed needed to “break free” from a gravitational field without further propulsion. A rocket moving out of gravity well does not actually need to attain escape velocity to do so, but could achieve the same result at any speed with a suitable mode of propulsion and sufficient fuel. Escape velocity only applies to ballistic trajectories.
[3] How much calories of energy is released by a boiled egg?
A.
40
B.
50
C.
60
D.
77
Ans:
77
Explanation :
77-78 calories are released in a large size boiled egg. Boiled eggs are eggs (typically chicken eggs) cooked by immersion in boiling water with their shells unbroken.
[4] Which combination of colour is the most convenient during day and night time?
A.
Organe and blue
B.
While and black
C.
Yellow and blue
D.
Red and green
Ans:
Red and green
Explanation :
Red and green is the most convenient combination during day and night time because of very precise visibility. In modern colour theory, also known as the RGB colour model, red, green and blue are additive primary colours. Red, green and blue light combined together makes white light, and these three colours, combined in different mixtures, can produce almost any colour. This is the principle used to make the colours on computer screen and television. The sRGB number of pure red, for example, is 255, 00, 00, which means the red component is at maximum intensity, and there is no green or blue. The sRGB number for crimson is 220, 20, 60, which means that the red is slightly l ess intense and therefore darker, there is some green, which leans it toward orange; and there is a larger amount of blue, which makes it slightly blue-violet.
[5] The instrument that measures and records the relative humidity of air is –
A.
Hydrometer
B.
Hygrometer
C.
Lactometer
D.
Barometer
Ans:
Hygrometer
Explanation :
A hygrometer is an instrument used for measuring the moisture content in the environment. Humidity measurement instruments usually rely on measurements of some other quantity such as temperature, pressure, mass or a mechanical or electrical change in a substance as moisture is absorbed. By calibration and calculation, these measured quantities can lead to a measurement of humidity.
[6] In a Laser (say neon laser) all the atoms emit the light waves of –
A.
Same frequency
B.
Same amplitude
C.
Same phase
D.
All of the above
Ans:
All of the above
Explanation :
In a Laser all the atoms emit the light waves of same frequency, amplitude and phase. A laser is a device that emits light (electromagnetic radiation) through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation.
[7] Which of the following celestial bodies contains abundant quantities of helium-3, a potential source of energy?
A.
Earth
B.
Moon
C.
Venus
D.
Saturn
Ans:
Moon
Explanation :
The Moon and other celestial bodies contain a vast amount of natural resources. One, and in abundance, is helium-3. It is estimated that forty tons of it can meet twenty five percent of the global energy demand for one year. This clean, nonradioactive and safe source of energy scarcely exists on Earth. Helium-3 derives from the dismantlement of old and outdated nuclear warheads. Helium-3 is used within medicine, scientific research, and well logging operations in the oil and gas industry, and for homeland security. Major space nations such as Russia, China, India, and Japan appear to have integrated within their space programmes to commercially exploit the Moon for helium-3 in the future.
[8] Smog is a combination of –
A.
Air and water vapours
B.
Water and smoke
C.
Fire and water
D.
Smoke and fog
Ans:
Smoke and fog
Explanation :
Smog is a type of air pollution; the word "smog" was coined in the early 20th century as a portmanteau of the words smoke and fog to refer to smoky fog. The word was then intended to refer to what was sometimes known as pea soup fog, a familiar and serious problem in London from the 19th century to the mid 20th century. This kind of smog is caused by the burning of large amounts of coal within a city; this smog contains soot particulates from smoke, sulfur dioxide and other components.
[9] When white light passes through a glass prism we get a spectrum on the other side of the prism. In the emergent beam the ray which is deviated least is -
A.
the violet ray
B.
the red ray
C.
the green ray
D.
the blue ray
Ans:
the red ray
Explanation :
Greater the wavelength smaller the deviation. Since the wavelength of red light is maximum, it will suffer least deviation.
[10] Study of life in outer space is known as -
A.
endbiology
B.
exobiology
C.
enterbiology
D.
neobiology
Ans:
exobiology
Explanation :
The study of life outside earth or extra-terrestrial life or alien life and the effects of extra terrestrial surroundings on living organism is known as Exobiology or Astrology or space biology. The hypothetical forms of life in space are of bacteria, and virus like organisms.
[11] Lens is made up of –
A.
Pyrex glass
B.
Flint glass
C.
Ordinary glass
D.
Cobalt glass
Ans:
Flint glass
Explanation :
Flint glass is optical glass that has relatively high refractive index and low Abbe number (high dispersion). A concave lens of flint glass is commonly combined with a convex lens of crown glass to produce an achromatic doublet lens because of their compensating optical properties, which reduces chromatic aberration (colour defects).
[12] The time period of a pendulum when taken to the Moon would:
A.
remain the same
B.
decrease
C.
become zero
D.
increase
Ans:
increase
Explanation :
Since the pendulum rate will increase with an increase in gravity, and local gravity varies with latitude and elevation on Earth, pendulum clocks must be readjusted to keep time after a move. For example, a pendulum clock moved from sea level to 4000 feet will lose 16 seconds per day.
[13] Pieces of camphor placed on water move about rapidly. This is because of -
A.
diffusion
B.
viscosity
C.
surface tension
D.
capillarity
Ans:
surface tension
Explanation :
The Camphor slowly dissolves in the water lowering the latter’s surface tension in the immediate neighborhood. The stronger pull exerted by the uncontaminated portion of water brings about a movement of the surface and the camphor particles are carried along with it.
[14] Lightning is caused due to –
A.
electric power
B.
electric discharge
C.
electric leak
D.
electric pressure
Ans:
electric discharge
Explanation :
Lightning is a discharge of electrical energy that builds up within a storm. The charges develop because a storm causes air to move around which rubs against itself to generate electrical charges. Eventually the charge increases to a point where the electricity can flow through the air
[15] Sprayer functions on –
A.
Bernouli’s principle
B.
Archeinecle's principle
C.
Pascal's law
D.
Floatation principle
Ans:
Bernouli’s principle
Explanation :
Bernoulli's principle states that as the speed of a moving fluid (liquid or gas) increases, the pressure within the liquid decreases. In the case of a sprayer, when the plunger is pushed in, the air flows at a high velocity through a nozzle, creating a region of low pressure above the metal tube. The higher pressure of the atmospheric air causes the liquid to rise up to the metal tube and come out as spray.
[16] Waves that are required for long distance wireless communication are –
A.
Infrared rays
B.
Ultraviolet rays
C.
Radio waves
D.
Microwaves
Ans:
Radio waves
Explanation :
Wireless communication is the transfer of information between two or more points that are not connected by an electrical conductor. With radio waves distances can be short, such as a few metres for television remote control, or as far as thousands or even millions of kilometres for deep-space radio communications.
[17] Rise of oil a wick is due to –
A.
density of the oil
B.
viscosity of the oil
C.
surface tension of the oil
D.
pressure of the oil
Ans:
surface tension of the oil
Explanation :
The phenomenon of rise or fall of liquid in a capillary tube is called capillarity. Oil rises through a wick due to capillarity. The narrow pores in the threads of a wick act like tiny capillaries, through which oil rises. Capillary action is the result of adhesion and surface tension.
[18] Heat stored in water vapour is –
A.
specific heat
B.
latent heat
C.
absolute heat
D.
relative heat
Ans:
latent heat
Explanation :
Latent heat is the heat released or absorbed by a body or a thermodynamic system during a process that occurs without a change in temperature. A typical example is a change of state of matter, meaning a phase transition such as the melting of ice or the boiling of water. So water vapor which is the end product of evaporated water has latent heat.
[19] The layer of atmosphere used for radio-wave transmission is –
A.
chromosphere
B.
troposphere
C.
ionosphere
D.
stratosphere
Ans:
ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere and 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.
[20] SI unit of luminous intensity is .
A.
lumen
B.
lux
C.
candela
D.
watt
Ans:
candela
Explanation :
Luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd).
[21] A rear-view mirror for driving is –
A.
plain
B.
concave
C.
convex
D.
inverted
Ans:
convex
Explanation :
The kind of mirror used in the rear-view mirror must be convex mirrors, because it creates smaller, yet still upright images. Concave mirrors would create an inverted image and the cars you see are not upside down. Convex mirrors make everything smaller so this allows the driver to see a greater range of things behind him.
[22] The important unit of a microprocessor is –
A.
ALU
B.
array of registers
C.
control unit
D.
All of the above
Ans:
All of the above
Explanation :
The basic units or blocks of a microprocessor are ALU, an array of registers and control unit. A minimal hypothetical microprocessor might only include an arithmetic logic unit (ALU) and a control logic section. Each operation of the ALU sets one or more flags in a status register, which indicate the results of the last operation (zero value, negative number, overflow or others).
[23] Which one of the following is an element of weather?
A.
Wind
B.
Temperature
C.
Humidity
D.
All options are correct
Ans:
All options are correct
Explanation :
There are many elements that make up both the weather and the climate of a geographical location. The most significant of these elements are temperature, atmospheric pressure, wind, solar energy. Humidity, precipitation, and topography.
[24] A periscope works on the principle of –
A.
refraction
B.
total internal reflection
C.
diffraction
D.
reflection
Ans:
total internal reflection
Explanation :
Total internal reflection (TIR) is the phenomenon that involves the reflection of the entire incident light off the boundary. Glass prisms can be shaped to produce total internal reflection and as such are employed in binoculars, periscopes, telescopes, and other optical instruments. For the prism used in periscope, the light rays hit the inside surface at an angle greater than the critical angle of 42 and hence they are internally reflected.
[25] A copper disc has a hole. If the disc is heated, the size of the hole -
A.
increases
B.
decreases
C.
No change
D.
first increases and than decreases
Ans:
increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.
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. Physically, rectifiers take a number of forms, including vacuum tube diodes, mercury-arc valves, solid- state diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches. Rectifiers have many uses, but are often found serving as components of DC power supplies and high-voltage direct current power transmission systems. Rectification may serve in roles other than to generate direct current for use as a source of power. As noted, detectors of radio signals serve as rectifiers.
[2] What is the minimum escape velocity of rocket to be launched into space?
A.
5 Km/Sec.
B.
6 Km/Sec.
C.
11 Km/Sec.
D.
15 Km/Sec.
Ans:
11 Km/Sec.
Explanation :
On the surface of the Earth, the escape velocity is about 11.2 kilometers per second (~6.96 mi/s), which is approximately 34 times the speed of sound (Mach 34) and several times the muzzle velocity of a rifle bullet (up to 1.7 km/s). However, at 9,000 km altitude in “space”, it is slightly less than 7.1 km/s. In physics, escape velocity is the speed at which the kinetic energy plus the gravitational potential energy of an object is zero. It is the speed needed to “break free” from a gravitational field without further propulsion. A rocket moving out of gravity well does not actually need to attain escape velocity to do so, but could achieve the same result at any speed with a suitable mode of propulsion and sufficient fuel. Escape velocity only applies to ballistic trajectories.
[3] How much calories of energy is released by a boiled egg?
A.
40
B.
50
C.
60
D.
77
Ans:
77
Explanation :
77-78 calories are released in a large size boiled egg. Boiled eggs are eggs (typically chicken eggs) cooked by immersion in boiling water with their shells unbroken.
[4] Which combination of colour is the most convenient during day and night time?
A.
Organe and blue
B.
While and black
C.
Yellow and blue
D.
Red and green
Ans:
Red and green
Explanation :
Red and green is the most convenient combination during day and night time because of very precise visibility. In modern colour theory, also known as the RGB colour model, red, green and blue are additive primary colours. Red, green and blue light combined together makes white light, and these three colours, combined in different mixtures, can produce almost any colour. This is the principle used to make the colours on computer screen and television. The sRGB number of pure red, for example, is 255, 00, 00, which means the red component is at maximum intensity, and there is no green or blue. The sRGB number for crimson is 220, 20, 60, which means that the red is slightly l ess intense and therefore darker, there is some green, which leans it toward orange; and there is a larger amount of blue, which makes it slightly blue-violet.
[5] The instrument that measures and records the relative humidity of air is –
A.
Hydrometer
B.
Hygrometer
C.
Lactometer
D.
Barometer
Ans:
Hygrometer
Explanation :
A hygrometer is an instrument used for measuring the moisture content in the environment. Humidity measurement instruments usually rely on measurements of some other quantity such as temperature, pressure, mass or a mechanical or electrical change in a substance as moisture is absorbed. By calibration and calculation, these measured quantities can lead to a measurement of humidity.
[6] In a Laser (say neon laser) all the atoms emit the light waves of –
A.
Same frequency
B.
Same amplitude
C.
Same phase
D.
All of the above
Ans:
All of the above
Explanation :
In a Laser all the atoms emit the light waves of same frequency, amplitude and phase. A laser is a device that emits light (electromagnetic radiation) through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation.
[7] Which of the following celestial bodies contains abundant quantities of helium-3, a potential source of energy?
A.
Earth
B.
Moon
C.
Venus
D.
Saturn
Ans:
Moon
Explanation :
The Moon and other celestial bodies contain a vast amount of natural resources. One, and in abundance, is helium-3. It is estimated that forty tons of it can meet twenty five percent of the global energy demand for one year. This clean, nonradioactive and safe source of energy scarcely exists on Earth. Helium-3 derives from the dismantlement of old and outdated nuclear warheads. Helium-3 is used within medicine, scientific research, and well logging operations in the oil and gas industry, and for homeland security. Major space nations such as Russia, China, India, and Japan appear to have integrated within their space programmes to commercially exploit the Moon for helium-3 in the future.
[8] Smog is a combination of –
A.
Air and water vapours
B.
Water and smoke
C.
Fire and water
D.
Smoke and fog
Ans:
Smoke and fog
Explanation :
Smog is a type of air pollution; the word "smog" was coined in the early 20th century as a portmanteau of the words smoke and fog to refer to smoky fog. The word was then intended to refer to what was sometimes known as pea soup fog, a familiar and serious problem in London from the 19th century to the mid 20th century. This kind of smog is caused by the burning of large amounts of coal within a city; this smog contains soot particulates from smoke, sulfur dioxide and other components.
[9] When white light passes through a glass prism we get a spectrum on the other side of the prism. In the emergent beam the ray which is deviated least is -
A.
the violet ray
B.
the red ray
C.
the green ray
D.
the blue ray
Ans:
the red ray
Explanation :
Greater the wavelength smaller the deviation. Since the wavelength of red light is maximum, it will suffer least deviation.
[10] Study of life in outer space is known as -
A.
endbiology
B.
exobiology
C.
enterbiology
D.
neobiology
Ans:
exobiology
Explanation :
The study of life outside earth or extra-terrestrial life or alien life and the effects of extra terrestrial surroundings on living organism is known as Exobiology or Astrology or space biology. The hypothetical forms of life in space are of bacteria, and virus like organisms.
[11] Lens is made up of –
A.
Pyrex glass
B.
Flint glass
C.
Ordinary glass
D.
Cobalt glass
Ans:
Flint glass
Explanation :
Flint glass is optical glass that has relatively high refractive index and low Abbe number (high dispersion). A concave lens of flint glass is commonly combined with a convex lens of crown glass to produce an achromatic doublet lens because of their compensating optical properties, which reduces chromatic aberration (colour defects).
[12] The time period of a pendulum when taken to the Moon would:
A.
remain the same
B.
decrease
C.
become zero
D.
increase
Ans:
increase
Explanation :
Since the pendulum rate will increase with an increase in gravity, and local gravity varies with latitude and elevation on Earth, pendulum clocks must be readjusted to keep time after a move. For example, a pendulum clock moved from sea level to 4000 feet will lose 16 seconds per day.
[13] Pieces of camphor placed on water move about rapidly. This is because of -
A.
diffusion
B.
viscosity
C.
surface tension
D.
capillarity
Ans:
surface tension
Explanation :
The Camphor slowly dissolves in the water lowering the latter’s surface tension in the immediate neighborhood. The stronger pull exerted by the uncontaminated portion of water brings about a movement of the surface and the camphor particles are carried along with it.
[14] Lightning is caused due to –
A.
electric power
B.
electric discharge
C.
electric leak
D.
electric pressure
Ans:
electric discharge
Explanation :
Lightning is a discharge of electrical energy that builds up within a storm. The charges develop because a storm causes air to move around which rubs against itself to generate electrical charges. Eventually the charge increases to a point where the electricity can flow through the air
[15] Sprayer functions on –
A.
Bernouli’s principle
B.
Archeinecle's principle
C.
Pascal's law
D.
Floatation principle
Ans:
Bernouli’s principle
Explanation :
Bernoulli's principle states that as the speed of a moving fluid (liquid or gas) increases, the pressure within the liquid decreases. In the case of a sprayer, when the plunger is pushed in, the air flows at a high velocity through a nozzle, creating a region of low pressure above the metal tube. The higher pressure of the atmospheric air causes the liquid to rise up to the metal tube and come out as spray.
[16] Waves that are required for long distance wireless communication are –
A.
Infrared rays
B.
Ultraviolet rays
C.
Radio waves
D.
Microwaves
Ans:
Radio waves
Explanation :
Wireless communication is the transfer of information between two or more points that are not connected by an electrical conductor. With radio waves distances can be short, such as a few metres for television remote control, or as far as thousands or even millions of kilometres for deep-space radio communications.
[17] Rise of oil a wick is due to –
A.
density of the oil
B.
viscosity of the oil
C.
surface tension of the oil
D.
pressure of the oil
Ans:
surface tension of the oil
Explanation :
The phenomenon of rise or fall of liquid in a capillary tube is called capillarity. Oil rises through a wick due to capillarity. The narrow pores in the threads of a wick act like tiny capillaries, through which oil rises. Capillary action is the result of adhesion and surface tension.
[18] Heat stored in water vapour is –
A.
specific heat
B.
latent heat
C.
absolute heat
D.
relative heat
Ans:
latent heat
Explanation :
Latent heat is the heat released or absorbed by a body or a thermodynamic system during a process that occurs without a change in temperature. A typical example is a change of state of matter, meaning a phase transition such as the melting of ice or the boiling of water. So water vapor which is the end product of evaporated water has latent heat.
[19] The layer of atmosphere used for radio-wave transmission is –
A.
chromosphere
B.
troposphere
C.
ionosphere
D.
stratosphere
Ans:
ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere and 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.
[20] SI unit of luminous intensity is .
A.
lumen
B.
lux
C.
candela
D.
watt
Ans:
candela
Explanation :
Luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd).
[21] A rear-view mirror for driving is –
A.
plain
B.
concave
C.
convex
D.
inverted
Ans:
convex
Explanation :
The kind of mirror used in the rear-view mirror must be convex mirrors, because it creates smaller, yet still upright images. Concave mirrors would create an inverted image and the cars you see are not upside down. Convex mirrors make everything smaller so this allows the driver to see a greater range of things behind him.
[22] The important unit of a microprocessor is –
A.
ALU
B.
array of registers
C.
control unit
D.
All of the above
Ans:
All of the above
Explanation :
The basic units or blocks of a microprocessor are ALU, an array of registers and control unit. A minimal hypothetical microprocessor might only include an arithmetic logic unit (ALU) and a control logic section. Each operation of the ALU sets one or more flags in a status register, which indicate the results of the last operation (zero value, negative number, overflow or others).
[23] Which one of the following is an element of weather?
A.
Wind
B.
Temperature
C.
Humidity
D.
All options are correct
Ans:
All options are correct
Explanation :
There are many elements that make up both the weather and the climate of a geographical location. The most significant of these elements are temperature, atmospheric pressure, wind, solar energy. Humidity, precipitation, and topography.
[24] A periscope works on the principle of –
A.
refraction
B.
total internal reflection
C.
diffraction
D.
reflection
Ans:
total internal reflection
Explanation :
Total internal reflection (TIR) is the phenomenon that involves the reflection of the entire incident light off the boundary. Glass prisms can be shaped to produce total internal reflection and as such are employed in binoculars, periscopes, telescopes, and other optical instruments. For the prism used in periscope, the light rays hit the inside surface at an angle greater than the critical angle of 42 and hence they are internally reflected.
[25] A copper disc has a hole. If the disc is heated, the size of the hole -
A.
increases
B.
decreases
C.
No change
D.
first increases and than decreases
Ans:
increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.
Explanation :
77-78 calories are released in a large size boiled egg. Boiled eggs are eggs (typically chicken eggs) cooked by immersion in boiling water with their shells unbroken.
[4] Which combination of colour is the most convenient during day and night time?
A.
Organe and blue
B.
While and black
C.
Yellow and blue
D.
Red and green
Ans:
Red and green
Explanation :
Red and green is the most convenient combination during day and night time because of very precise visibility. In modern colour theory, also known as the RGB colour model, red, green and blue are additive primary colours. Red, green and blue light combined together makes white light, and these three colours, combined in different mixtures, can produce almost any colour. This is the principle used to make the colours on computer screen and television. The sRGB number of pure red, for example, is 255, 00, 00, which means the red component is at maximum intensity, and there is no green or blue. The sRGB number for crimson is 220, 20, 60, which means that the red is slightly l ess intense and therefore darker, there is some green, which leans it toward orange; and there is a larger amount of blue, which makes it slightly blue-violet.
[5] The instrument that measures and records the relative humidity of air is –
A.
Hydrometer
B.
Hygrometer
C.
Lactometer
D.
Barometer
Ans:
Hygrometer
Explanation :
A hygrometer is an instrument used for measuring the moisture content in the environment. Humidity measurement instruments usually rely on measurements of some other quantity such as temperature, pressure, mass or a mechanical or electrical change in a substance as moisture is absorbed. By calibration and calculation, these measured quantities can lead to a measurement of humidity.
[6] In a Laser (say neon laser) all the atoms emit the light waves of –
A.
Same frequency
B.
Same amplitude
C.
Same phase
D.
All of the above
Ans:
All of the above
Explanation :
In a Laser all the atoms emit the light waves of same frequency, amplitude and phase. A laser is a device that emits light (electromagnetic radiation) through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation.
[7] Which of the following celestial bodies contains abundant quantities of helium-3, a potential source of energy?
A.
Earth
B.
Moon
C.
Venus
D.
Saturn
Ans:
Moon
Explanation :
The Moon and other celestial bodies contain a vast amount of natural resources. One, and in abundance, is helium-3. It is estimated that forty tons of it can meet twenty five percent of the global energy demand for one year. This clean, nonradioactive and safe source of energy scarcely exists on Earth. Helium-3 derives from the dismantlement of old and outdated nuclear warheads. Helium-3 is used within medicine, scientific research, and well logging operations in the oil and gas industry, and for homeland security. Major space nations such as Russia, China, India, and Japan appear to have integrated within their space programmes to commercially exploit the Moon for helium-3 in the future.
[8] Smog is a combination of –
A.
Air and water vapours
B.
Water and smoke
C.
Fire and water
D.
Smoke and fog
Ans:
Smoke and fog
Explanation :
Smog is a type of air pollution; the word "smog" was coined in the early 20th century as a portmanteau of the words smoke and fog to refer to smoky fog. The word was then intended to refer to what was sometimes known as pea soup fog, a familiar and serious problem in London from the 19th century to the mid 20th century. This kind of smog is caused by the burning of large amounts of coal within a city; this smog contains soot particulates from smoke, sulfur dioxide and other components.
[9] When white light passes through a glass prism we get a spectrum on the other side of the prism. In the emergent beam the ray which is deviated least is -
A.
the violet ray
B.
the red ray
C.
the green ray
D.
the blue ray
Ans:
the red ray
Explanation :
Greater the wavelength smaller the deviation. Since the wavelength of red light is maximum, it will suffer least deviation.
[10] Study of life in outer space is known as -
A.
endbiology
B.
exobiology
C.
enterbiology
D.
neobiology
Ans:
exobiology
Explanation :
The study of life outside earth or extra-terrestrial life or alien life and the effects of extra terrestrial surroundings on living organism is known as Exobiology or Astrology or space biology. The hypothetical forms of life in space are of bacteria, and virus like organisms.
[11] Lens is made up of –
A.
Pyrex glass
B.
Flint glass
C.
Ordinary glass
D.
Cobalt glass
Ans:
Flint glass
Explanation :
Flint glass is optical glass that has relatively high refractive index and low Abbe number (high dispersion). A concave lens of flint glass is commonly combined with a convex lens of crown glass to produce an achromatic doublet lens because of their compensating optical properties, which reduces chromatic aberration (colour defects).
[12] The time period of a pendulum when taken to the Moon would:
A.
remain the same
B.
decrease
C.
become zero
D.
increase
Ans:
increase
Explanation :
Since the pendulum rate will increase with an increase in gravity, and local gravity varies with latitude and elevation on Earth, pendulum clocks must be readjusted to keep time after a move. For example, a pendulum clock moved from sea level to 4000 feet will lose 16 seconds per day.
[13] Pieces of camphor placed on water move about rapidly. This is because of -
A.
diffusion
B.
viscosity
C.
surface tension
D.
capillarity
Ans:
surface tension
Explanation :
The Camphor slowly dissolves in the water lowering the latter’s surface tension in the immediate neighborhood. The stronger pull exerted by the uncontaminated portion of water brings about a movement of the surface and the camphor particles are carried along with it.
[14] Lightning is caused due to –
A.
electric power
B.
electric discharge
C.
electric leak
D.
electric pressure
Ans:
electric discharge
Explanation :
Lightning is a discharge of electrical energy that builds up within a storm. The charges develop because a storm causes air to move around which rubs against itself to generate electrical charges. Eventually the charge increases to a point where the electricity can flow through the air
[15] Sprayer functions on –
A.
Bernouli’s principle
B.
Archeinecle's principle
C.
Pascal's law
D.
Floatation principle
Ans:
Bernouli’s principle
Explanation :
Bernoulli's principle states that as the speed of a moving fluid (liquid or gas) increases, the pressure within the liquid decreases. In the case of a sprayer, when the plunger is pushed in, the air flows at a high velocity through a nozzle, creating a region of low pressure above the metal tube. The higher pressure of the atmospheric air causes the liquid to rise up to the metal tube and come out as spray.
[16] Waves that are required for long distance wireless communication are –
A.
Infrared rays
B.
Ultraviolet rays
C.
Radio waves
D.
Microwaves
Ans:
Radio waves
Explanation :
Wireless communication is the transfer of information between two or more points that are not connected by an electrical conductor. With radio waves distances can be short, such as a few metres for television remote control, or as far as thousands or even millions of kilometres for deep-space radio communications.
[17] Rise of oil a wick is due to –
A.
density of the oil
B.
viscosity of the oil
C.
surface tension of the oil
D.
pressure of the oil
Ans:
surface tension of the oil
Explanation :
The phenomenon of rise or fall of liquid in a capillary tube is called capillarity. Oil rises through a wick due to capillarity. The narrow pores in the threads of a wick act like tiny capillaries, through which oil rises. Capillary action is the result of adhesion and surface tension.
[18] Heat stored in water vapour is –
A.
specific heat
B.
latent heat
C.
absolute heat
D.
relative heat
Ans:
latent heat
Explanation :
Latent heat is the heat released or absorbed by a body or a thermodynamic system during a process that occurs without a change in temperature. A typical example is a change of state of matter, meaning a phase transition such as the melting of ice or the boiling of water. So water vapor which is the end product of evaporated water has latent heat.
[19] The layer of atmosphere used for radio-wave transmission is –
A.
chromosphere
B.
troposphere
C.
ionosphere
D.
stratosphere
Ans:
ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere and 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.
[20] SI unit of luminous intensity is .
A.
lumen
B.
lux
C.
candela
D.
watt
Ans:
candela
Explanation :
Luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd).
[21] A rear-view mirror for driving is –
A.
plain
B.
concave
C.
convex
D.
inverted
Ans:
convex
Explanation :
The kind of mirror used in the rear-view mirror must be convex mirrors, because it creates smaller, yet still upright images. Concave mirrors would create an inverted image and the cars you see are not upside down. Convex mirrors make everything smaller so this allows the driver to see a greater range of things behind him.
[22] The important unit of a microprocessor is –
A.
ALU
B.
array of registers
C.
control unit
D.
All of the above
Ans:
All of the above
Explanation :
The basic units or blocks of a microprocessor are ALU, an array of registers and control unit. A minimal hypothetical microprocessor might only include an arithmetic logic unit (ALU) and a control logic section. Each operation of the ALU sets one or more flags in a status register, which indicate the results of the last operation (zero value, negative number, overflow or others).
[23] Which one of the following is an element of weather?
A.
Wind
B.
Temperature
C.
Humidity
D.
All options are correct
Ans:
All options are correct
Explanation :
There are many elements that make up both the weather and the climate of a geographical location. The most significant of these elements are temperature, atmospheric pressure, wind, solar energy. Humidity, precipitation, and topography.
[24] A periscope works on the principle of –
A.
refraction
B.
total internal reflection
C.
diffraction
D.
reflection
Ans:
total internal reflection
Explanation :
Total internal reflection (TIR) is the phenomenon that involves the reflection of the entire incident light off the boundary. Glass prisms can be shaped to produce total internal reflection and as such are employed in binoculars, periscopes, telescopes, and other optical instruments. For the prism used in periscope, the light rays hit the inside surface at an angle greater than the critical angle of 42 and hence they are internally reflected.
[25] A copper disc has a hole. If the disc is heated, the size of the hole -
A.
increases
B.
decreases
C.
No change
D.
first increases and than decreases
Ans:
increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.
Explanation :
A hygrometer is an instrument used for measuring the moisture content in the environment. Humidity measurement instruments usually rely on measurements of some other quantity such as temperature, pressure, mass or a mechanical or electrical change in a substance as moisture is absorbed. By calibration and calculation, these measured quantities can lead to a measurement of humidity.
[6] In a Laser (say neon laser) all the atoms emit the light waves of –
A.
Same frequency
B.
Same amplitude
C.
Same phase
D.
All of the above
Ans:
All of the above
Explanation :
In a Laser all the atoms emit the light waves of same frequency, amplitude and phase. A laser is a device that emits light (electromagnetic radiation) through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation.
[7] Which of the following celestial bodies contains abundant quantities of helium-3, a potential source of energy?
A.
Earth
B.
Moon
C.
Venus
D.
Saturn
Ans:
Moon
Explanation :
The Moon and other celestial bodies contain a vast amount of natural resources. One, and in abundance, is helium-3. It is estimated that forty tons of it can meet twenty five percent of the global energy demand for one year. This clean, nonradioactive and safe source of energy scarcely exists on Earth. Helium-3 derives from the dismantlement of old and outdated nuclear warheads. Helium-3 is used within medicine, scientific research, and well logging operations in the oil and gas industry, and for homeland security. Major space nations such as Russia, China, India, and Japan appear to have integrated within their space programmes to commercially exploit the Moon for helium-3 in the future.
[8] Smog is a combination of –
A.
Air and water vapours
B.
Water and smoke
C.
Fire and water
D.
Smoke and fog
Ans:
Smoke and fog
Explanation :
Smog is a type of air pollution; the word "smog" was coined in the early 20th century as a portmanteau of the words smoke and fog to refer to smoky fog. The word was then intended to refer to what was sometimes known as pea soup fog, a familiar and serious problem in London from the 19th century to the mid 20th century. This kind of smog is caused by the burning of large amounts of coal within a city; this smog contains soot particulates from smoke, sulfur dioxide and other components.
[9] When white light passes through a glass prism we get a spectrum on the other side of the prism. In the emergent beam the ray which is deviated least is -
A.
the violet ray
B.
the red ray
C.
the green ray
D.
the blue ray
Ans:
the red ray
Explanation :
Greater the wavelength smaller the deviation. Since the wavelength of red light is maximum, it will suffer least deviation.
[10] Study of life in outer space is known as -
A.
endbiology
B.
exobiology
C.
enterbiology
D.
neobiology
Ans:
exobiology
Explanation :
The study of life outside earth or extra-terrestrial life or alien life and the effects of extra terrestrial surroundings on living organism is known as Exobiology or Astrology or space biology. The hypothetical forms of life in space are of bacteria, and virus like organisms.
[11] Lens is made up of –
A.
Pyrex glass
B.
Flint glass
C.
Ordinary glass
D.
Cobalt glass
Ans:
Flint glass
Explanation :
Flint glass is optical glass that has relatively high refractive index and low Abbe number (high dispersion). A concave lens of flint glass is commonly combined with a convex lens of crown glass to produce an achromatic doublet lens because of their compensating optical properties, which reduces chromatic aberration (colour defects).
[12] The time period of a pendulum when taken to the Moon would:
A.
remain the same
B.
decrease
C.
become zero
D.
increase
Ans:
increase
Explanation :
Since the pendulum rate will increase with an increase in gravity, and local gravity varies with latitude and elevation on Earth, pendulum clocks must be readjusted to keep time after a move. For example, a pendulum clock moved from sea level to 4000 feet will lose 16 seconds per day.
[13] Pieces of camphor placed on water move about rapidly. This is because of -
A.
diffusion
B.
viscosity
C.
surface tension
D.
capillarity
Ans:
surface tension
Explanation :
The Camphor slowly dissolves in the water lowering the latter’s surface tension in the immediate neighborhood. The stronger pull exerted by the uncontaminated portion of water brings about a movement of the surface and the camphor particles are carried along with it.
[14] Lightning is caused due to –
A.
electric power
B.
electric discharge
C.
electric leak
D.
electric pressure
Ans:
electric discharge
Explanation :
Lightning is a discharge of electrical energy that builds up within a storm. The charges develop because a storm causes air to move around which rubs against itself to generate electrical charges. Eventually the charge increases to a point where the electricity can flow through the air
[15] Sprayer functions on –
A.
Bernouli’s principle
B.
Archeinecle's principle
C.
Pascal's law
D.
Floatation principle
Ans:
Bernouli’s principle
Explanation :
Bernoulli's principle states that as the speed of a moving fluid (liquid or gas) increases, the pressure within the liquid decreases. In the case of a sprayer, when the plunger is pushed in, the air flows at a high velocity through a nozzle, creating a region of low pressure above the metal tube. The higher pressure of the atmospheric air causes the liquid to rise up to the metal tube and come out as spray.
[16] Waves that are required for long distance wireless communication are –
A.
Infrared rays
B.
Ultraviolet rays
C.
Radio waves
D.
Microwaves
Ans:
Radio waves
Explanation :
Wireless communication is the transfer of information between two or more points that are not connected by an electrical conductor. With radio waves distances can be short, such as a few metres for television remote control, or as far as thousands or even millions of kilometres for deep-space radio communications.
[17] Rise of oil a wick is due to –
A.
density of the oil
B.
viscosity of the oil
C.
surface tension of the oil
D.
pressure of the oil
Ans:
surface tension of the oil
Explanation :
The phenomenon of rise or fall of liquid in a capillary tube is called capillarity. Oil rises through a wick due to capillarity. The narrow pores in the threads of a wick act like tiny capillaries, through which oil rises. Capillary action is the result of adhesion and surface tension.
[18] Heat stored in water vapour is –
A.
specific heat
B.
latent heat
C.
absolute heat
D.
relative heat
Ans:
latent heat
Explanation :
Latent heat is the heat released or absorbed by a body or a thermodynamic system during a process that occurs without a change in temperature. A typical example is a change of state of matter, meaning a phase transition such as the melting of ice or the boiling of water. So water vapor which is the end product of evaporated water has latent heat.
[19] The layer of atmosphere used for radio-wave transmission is –
A.
chromosphere
B.
troposphere
C.
ionosphere
D.
stratosphere
Ans:
ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere and 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.
[20] SI unit of luminous intensity is .
A.
lumen
B.
lux
C.
candela
D.
watt
Ans:
candela
Explanation :
Luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd).
[21] A rear-view mirror for driving is –
A.
plain
B.
concave
C.
convex
D.
inverted
Ans:
convex
Explanation :
The kind of mirror used in the rear-view mirror must be convex mirrors, because it creates smaller, yet still upright images. Concave mirrors would create an inverted image and the cars you see are not upside down. Convex mirrors make everything smaller so this allows the driver to see a greater range of things behind him.
[22] The important unit of a microprocessor is –
A.
ALU
B.
array of registers
C.
control unit
D.
All of the above
Ans:
All of the above
Explanation :
The basic units or blocks of a microprocessor are ALU, an array of registers and control unit. A minimal hypothetical microprocessor might only include an arithmetic logic unit (ALU) and a control logic section. Each operation of the ALU sets one or more flags in a status register, which indicate the results of the last operation (zero value, negative number, overflow or others).
[23] Which one of the following is an element of weather?
A.
Wind
B.
Temperature
C.
Humidity
D.
All options are correct
Ans:
All options are correct
Explanation :
There are many elements that make up both the weather and the climate of a geographical location. The most significant of these elements are temperature, atmospheric pressure, wind, solar energy. Humidity, precipitation, and topography.
[24] A periscope works on the principle of –
A.
refraction
B.
total internal reflection
C.
diffraction
D.
reflection
Ans:
total internal reflection
Explanation :
Total internal reflection (TIR) is the phenomenon that involves the reflection of the entire incident light off the boundary. Glass prisms can be shaped to produce total internal reflection and as such are employed in binoculars, periscopes, telescopes, and other optical instruments. For the prism used in periscope, the light rays hit the inside surface at an angle greater than the critical angle of 42 and hence they are internally reflected.
[25] A copper disc has a hole. If the disc is heated, the size of the hole -
A.
increases
B.
decreases
C.
No change
D.
first increases and than decreases
Ans:
increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.
Explanation :
The Moon and other celestial bodies contain a vast amount of natural resources. One, and in abundance, is helium-3. It is estimated that forty tons of it can meet twenty five percent of the global energy demand for one year. This clean, nonradioactive and safe source of energy scarcely exists on Earth. Helium-3 derives from the dismantlement of old and outdated nuclear warheads. Helium-3 is used within medicine, scientific research, and well logging operations in the oil and gas industry, and for homeland security. Major space nations such as Russia, China, India, and Japan appear to have integrated within their space programmes to commercially exploit the Moon for helium-3 in the future.
[8] Smog is a combination of –
A.
Air and water vapours
B.
Water and smoke
C.
Fire and water
D.
Smoke and fog
Ans:
Smoke and fog
Explanation :
Smog is a type of air pollution; the word "smog" was coined in the early 20th century as a portmanteau of the words smoke and fog to refer to smoky fog. The word was then intended to refer to what was sometimes known as pea soup fog, a familiar and serious problem in London from the 19th century to the mid 20th century. This kind of smog is caused by the burning of large amounts of coal within a city; this smog contains soot particulates from smoke, sulfur dioxide and other components.
[9] When white light passes through a glass prism we get a spectrum on the other side of the prism. In the emergent beam the ray which is deviated least is -
A.
the violet ray
B.
the red ray
C.
the green ray
D.
the blue ray
Ans:
the red ray
Explanation :
Greater the wavelength smaller the deviation. Since the wavelength of red light is maximum, it will suffer least deviation.
[10] Study of life in outer space is known as -
A.
endbiology
B.
exobiology
C.
enterbiology
D.
neobiology
Ans:
exobiology
Explanation :
The study of life outside earth or extra-terrestrial life or alien life and the effects of extra terrestrial surroundings on living organism is known as Exobiology or Astrology or space biology. The hypothetical forms of life in space are of bacteria, and virus like organisms.
[11] Lens is made up of –
A.
Pyrex glass
B.
Flint glass
C.
Ordinary glass
D.
Cobalt glass
Ans:
Flint glass
Explanation :
Flint glass is optical glass that has relatively high refractive index and low Abbe number (high dispersion). A concave lens of flint glass is commonly combined with a convex lens of crown glass to produce an achromatic doublet lens because of their compensating optical properties, which reduces chromatic aberration (colour defects).
[12] The time period of a pendulum when taken to the Moon would:
A.
remain the same
B.
decrease
C.
become zero
D.
increase
Ans:
increase
Explanation :
Since the pendulum rate will increase with an increase in gravity, and local gravity varies with latitude and elevation on Earth, pendulum clocks must be readjusted to keep time after a move. For example, a pendulum clock moved from sea level to 4000 feet will lose 16 seconds per day.
[13] Pieces of camphor placed on water move about rapidly. This is because of -
A.
diffusion
B.
viscosity
C.
surface tension
D.
capillarity
Ans:
surface tension
Explanation :
The Camphor slowly dissolves in the water lowering the latter’s surface tension in the immediate neighborhood. The stronger pull exerted by the uncontaminated portion of water brings about a movement of the surface and the camphor particles are carried along with it.
[14] Lightning is caused due to –
A.
electric power
B.
electric discharge
C.
electric leak
D.
electric pressure
Ans:
electric discharge
Explanation :
Lightning is a discharge of electrical energy that builds up within a storm. The charges develop because a storm causes air to move around which rubs against itself to generate electrical charges. Eventually the charge increases to a point where the electricity can flow through the air
[15] Sprayer functions on –
A.
Bernouli’s principle
B.
Archeinecle's principle
C.
Pascal's law
D.
Floatation principle
Ans:
Bernouli’s principle
Explanation :
Bernoulli's principle states that as the speed of a moving fluid (liquid or gas) increases, the pressure within the liquid decreases. In the case of a sprayer, when the plunger is pushed in, the air flows at a high velocity through a nozzle, creating a region of low pressure above the metal tube. The higher pressure of the atmospheric air causes the liquid to rise up to the metal tube and come out as spray.
[16] Waves that are required for long distance wireless communication are –
A.
Infrared rays
B.
Ultraviolet rays
C.
Radio waves
D.
Microwaves
Ans:
Radio waves
Explanation :
Wireless communication is the transfer of information between two or more points that are not connected by an electrical conductor. With radio waves distances can be short, such as a few metres for television remote control, or as far as thousands or even millions of kilometres for deep-space radio communications.
[17] Rise of oil a wick is due to –
A.
density of the oil
B.
viscosity of the oil
C.
surface tension of the oil
D.
pressure of the oil
Ans:
surface tension of the oil
Explanation :
The phenomenon of rise or fall of liquid in a capillary tube is called capillarity. Oil rises through a wick due to capillarity. The narrow pores in the threads of a wick act like tiny capillaries, through which oil rises. Capillary action is the result of adhesion and surface tension.
[18] Heat stored in water vapour is –
A.
specific heat
B.
latent heat
C.
absolute heat
D.
relative heat
Ans:
latent heat
Explanation :
Latent heat is the heat released or absorbed by a body or a thermodynamic system during a process that occurs without a change in temperature. A typical example is a change of state of matter, meaning a phase transition such as the melting of ice or the boiling of water. So water vapor which is the end product of evaporated water has latent heat.
[19] The layer of atmosphere used for radio-wave transmission is –
A.
chromosphere
B.
troposphere
C.
ionosphere
D.
stratosphere
Ans:
ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere and 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.
[20] SI unit of luminous intensity is .
A.
lumen
B.
lux
C.
candela
D.
watt
Ans:
candela
Explanation :
Luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd).
[21] A rear-view mirror for driving is –
A.
plain
B.
concave
C.
convex
D.
inverted
Ans:
convex
Explanation :
The kind of mirror used in the rear-view mirror must be convex mirrors, because it creates smaller, yet still upright images. Concave mirrors would create an inverted image and the cars you see are not upside down. Convex mirrors make everything smaller so this allows the driver to see a greater range of things behind him.
[22] The important unit of a microprocessor is –
A.
ALU
B.
array of registers
C.
control unit
D.
All of the above
Ans:
All of the above
Explanation :
The basic units or blocks of a microprocessor are ALU, an array of registers and control unit. A minimal hypothetical microprocessor might only include an arithmetic logic unit (ALU) and a control logic section. Each operation of the ALU sets one or more flags in a status register, which indicate the results of the last operation (zero value, negative number, overflow or others).
[23] Which one of the following is an element of weather?
A.
Wind
B.
Temperature
C.
Humidity
D.
All options are correct
Ans:
All options are correct
Explanation :
There are many elements that make up both the weather and the climate of a geographical location. The most significant of these elements are temperature, atmospheric pressure, wind, solar energy. Humidity, precipitation, and topography.
[24] A periscope works on the principle of –
A.
refraction
B.
total internal reflection
C.
diffraction
D.
reflection
Ans:
total internal reflection
Explanation :
Total internal reflection (TIR) is the phenomenon that involves the reflection of the entire incident light off the boundary. Glass prisms can be shaped to produce total internal reflection and as such are employed in binoculars, periscopes, telescopes, and other optical instruments. For the prism used in periscope, the light rays hit the inside surface at an angle greater than the critical angle of 42 and hence they are internally reflected.
[25] A copper disc has a hole. If the disc is heated, the size of the hole -
A.
increases
B.
decreases
C.
No change
D.
first increases and than decreases
Ans:
increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.
Explanation :
Greater the wavelength smaller the deviation. Since the wavelength of red light is maximum, it will suffer least deviation.
[10] Study of life in outer space is known as -
A.
endbiology
B.
exobiology
C.
enterbiology
D.
neobiology
Ans:
exobiology
Explanation :
The study of life outside earth or extra-terrestrial life or alien life and the effects of extra terrestrial surroundings on living organism is known as Exobiology or Astrology or space biology. The hypothetical forms of life in space are of bacteria, and virus like organisms.
[11] Lens is made up of –
A.
Pyrex glass
B.
Flint glass
C.
Ordinary glass
D.
Cobalt glass
Ans:
Flint glass
Explanation :
Flint glass is optical glass that has relatively high refractive index and low Abbe number (high dispersion). A concave lens of flint glass is commonly combined with a convex lens of crown glass to produce an achromatic doublet lens because of their compensating optical properties, which reduces chromatic aberration (colour defects).
[12] The time period of a pendulum when taken to the Moon would:
A.
remain the same
B.
decrease
C.
become zero
D.
increase
Ans:
increase
Explanation :
Since the pendulum rate will increase with an increase in gravity, and local gravity varies with latitude and elevation on Earth, pendulum clocks must be readjusted to keep time after a move. For example, a pendulum clock moved from sea level to 4000 feet will lose 16 seconds per day.
[13] Pieces of camphor placed on water move about rapidly. This is because of -
A.
diffusion
B.
viscosity
C.
surface tension
D.
capillarity
Ans:
surface tension
Explanation :
The Camphor slowly dissolves in the water lowering the latter’s surface tension in the immediate neighborhood. The stronger pull exerted by the uncontaminated portion of water brings about a movement of the surface and the camphor particles are carried along with it.
[14] Lightning is caused due to –
A.
electric power
B.
electric discharge
C.
electric leak
D.
electric pressure
Ans:
electric discharge
Explanation :
Lightning is a discharge of electrical energy that builds up within a storm. The charges develop because a storm causes air to move around which rubs against itself to generate electrical charges. Eventually the charge increases to a point where the electricity can flow through the air
[15] Sprayer functions on –
A.
Bernouli’s principle
B.
Archeinecle's principle
C.
Pascal's law
D.
Floatation principle
Ans:
Bernouli’s principle
Explanation :
Bernoulli's principle states that as the speed of a moving fluid (liquid or gas) increases, the pressure within the liquid decreases. In the case of a sprayer, when the plunger is pushed in, the air flows at a high velocity through a nozzle, creating a region of low pressure above the metal tube. The higher pressure of the atmospheric air causes the liquid to rise up to the metal tube and come out as spray.
[16] Waves that are required for long distance wireless communication are –
A.
Infrared rays
B.
Ultraviolet rays
C.
Radio waves
D.
Microwaves
Ans:
Radio waves
Explanation :
Wireless communication is the transfer of information between two or more points that are not connected by an electrical conductor. With radio waves distances can be short, such as a few metres for television remote control, or as far as thousands or even millions of kilometres for deep-space radio communications.
[17] Rise of oil a wick is due to –
A.
density of the oil
B.
viscosity of the oil
C.
surface tension of the oil
D.
pressure of the oil
Ans:
surface tension of the oil
Explanation :
The phenomenon of rise or fall of liquid in a capillary tube is called capillarity. Oil rises through a wick due to capillarity. The narrow pores in the threads of a wick act like tiny capillaries, through which oil rises. Capillary action is the result of adhesion and surface tension.
[18] Heat stored in water vapour is –
A.
specific heat
B.
latent heat
C.
absolute heat
D.
relative heat
Ans:
latent heat
Explanation :
Latent heat is the heat released or absorbed by a body or a thermodynamic system during a process that occurs without a change in temperature. A typical example is a change of state of matter, meaning a phase transition such as the melting of ice or the boiling of water. So water vapor which is the end product of evaporated water has latent heat.
[19] The layer of atmosphere used for radio-wave transmission is –
A.
chromosphere
B.
troposphere
C.
ionosphere
D.
stratosphere
Ans:
ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere and 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.
[20] SI unit of luminous intensity is .
A.
lumen
B.
lux
C.
candela
D.
watt
Ans:
candela
Explanation :
Luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd).
[21] A rear-view mirror for driving is –
A.
plain
B.
concave
C.
convex
D.
inverted
Ans:
convex
Explanation :
The kind of mirror used in the rear-view mirror must be convex mirrors, because it creates smaller, yet still upright images. Concave mirrors would create an inverted image and the cars you see are not upside down. Convex mirrors make everything smaller so this allows the driver to see a greater range of things behind him.
[22] The important unit of a microprocessor is –
A.
ALU
B.
array of registers
C.
control unit
D.
All of the above
Ans:
All of the above
Explanation :
The basic units or blocks of a microprocessor are ALU, an array of registers and control unit. A minimal hypothetical microprocessor might only include an arithmetic logic unit (ALU) and a control logic section. Each operation of the ALU sets one or more flags in a status register, which indicate the results of the last operation (zero value, negative number, overflow or others).
[23] Which one of the following is an element of weather?
A.
Wind
B.
Temperature
C.
Humidity
D.
All options are correct
Ans:
All options are correct
Explanation :
There are many elements that make up both the weather and the climate of a geographical location. The most significant of these elements are temperature, atmospheric pressure, wind, solar energy. Humidity, precipitation, and topography.
[24] A periscope works on the principle of –
A.
refraction
B.
total internal reflection
C.
diffraction
D.
reflection
Ans:
total internal reflection
Explanation :
Total internal reflection (TIR) is the phenomenon that involves the reflection of the entire incident light off the boundary. Glass prisms can be shaped to produce total internal reflection and as such are employed in binoculars, periscopes, telescopes, and other optical instruments. For the prism used in periscope, the light rays hit the inside surface at an angle greater than the critical angle of 42 and hence they are internally reflected.
[25] A copper disc has a hole. If the disc is heated, the size of the hole -
A.
increases
B.
decreases
C.
No change
D.
first increases and than decreases
Ans:
increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.
Explanation :
Flint glass is optical glass that has relatively high refractive index and low Abbe number (high dispersion). A concave lens of flint glass is commonly combined with a convex lens of crown glass to produce an achromatic doublet lens because of their compensating optical properties, which reduces chromatic aberration (colour defects).
[12] The time period of a pendulum when taken to the Moon would:
A.
remain the same
B.
decrease
C.
become zero
D.
increase
Ans:
increase
Explanation :
Since the pendulum rate will increase with an increase in gravity, and local gravity varies with latitude and elevation on Earth, pendulum clocks must be readjusted to keep time after a move. For example, a pendulum clock moved from sea level to 4000 feet will lose 16 seconds per day.
[13] Pieces of camphor placed on water move about rapidly. This is because of -
A.
diffusion
B.
viscosity
C.
surface tension
D.
capillarity
Ans:
surface tension
Explanation :
The Camphor slowly dissolves in the water lowering the latter’s surface tension in the immediate neighborhood. The stronger pull exerted by the uncontaminated portion of water brings about a movement of the surface and the camphor particles are carried along with it.
[14] Lightning is caused due to –
A.
electric power
B.
electric discharge
C.
electric leak
D.
electric pressure
Ans:
electric discharge
Explanation :
Lightning is a discharge of electrical energy that builds up within a storm. The charges develop because a storm causes air to move around which rubs against itself to generate electrical charges. Eventually the charge increases to a point where the electricity can flow through the air
[15] Sprayer functions on –
A.
Bernouli’s principle
B.
Archeinecle's principle
C.
Pascal's law
D.
Floatation principle
Ans:
Bernouli’s principle
Explanation :
Bernoulli's principle states that as the speed of a moving fluid (liquid or gas) increases, the pressure within the liquid decreases. In the case of a sprayer, when the plunger is pushed in, the air flows at a high velocity through a nozzle, creating a region of low pressure above the metal tube. The higher pressure of the atmospheric air causes the liquid to rise up to the metal tube and come out as spray.
[16] Waves that are required for long distance wireless communication are –
A.
Infrared rays
B.
Ultraviolet rays
C.
Radio waves
D.
Microwaves
Ans:
Radio waves
Explanation :
Wireless communication is the transfer of information between two or more points that are not connected by an electrical conductor. With radio waves distances can be short, such as a few metres for television remote control, or as far as thousands or even millions of kilometres for deep-space radio communications.
[17] Rise of oil a wick is due to –
A.
density of the oil
B.
viscosity of the oil
C.
surface tension of the oil
D.
pressure of the oil
Ans:
surface tension of the oil
Explanation :
The phenomenon of rise or fall of liquid in a capillary tube is called capillarity. Oil rises through a wick due to capillarity. The narrow pores in the threads of a wick act like tiny capillaries, through which oil rises. Capillary action is the result of adhesion and surface tension.
[18] Heat stored in water vapour is –
A.
specific heat
B.
latent heat
C.
absolute heat
D.
relative heat
Ans:
latent heat
Explanation :
Latent heat is the heat released or absorbed by a body or a thermodynamic system during a process that occurs without a change in temperature. A typical example is a change of state of matter, meaning a phase transition such as the melting of ice or the boiling of water. So water vapor which is the end product of evaporated water has latent heat.
[19] The layer of atmosphere used for radio-wave transmission is –
A.
chromosphere
B.
troposphere
C.
ionosphere
D.
stratosphere
Ans:
ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere and 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.
[20] SI unit of luminous intensity is .
A.
lumen
B.
lux
C.
candela
D.
watt
Ans:
candela
Explanation :
Luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd).
[21] A rear-view mirror for driving is –
A.
plain
B.
concave
C.
convex
D.
inverted
Ans:
convex
Explanation :
The kind of mirror used in the rear-view mirror must be convex mirrors, because it creates smaller, yet still upright images. Concave mirrors would create an inverted image and the cars you see are not upside down. Convex mirrors make everything smaller so this allows the driver to see a greater range of things behind him.
[22] The important unit of a microprocessor is –
A.
ALU
B.
array of registers
C.
control unit
D.
All of the above
Ans:
All of the above
Explanation :
The basic units or blocks of a microprocessor are ALU, an array of registers and control unit. A minimal hypothetical microprocessor might only include an arithmetic logic unit (ALU) and a control logic section. Each operation of the ALU sets one or more flags in a status register, which indicate the results of the last operation (zero value, negative number, overflow or others).
[23] Which one of the following is an element of weather?
A.
Wind
B.
Temperature
C.
Humidity
D.
All options are correct
Ans:
All options are correct
Explanation :
There are many elements that make up both the weather and the climate of a geographical location. The most significant of these elements are temperature, atmospheric pressure, wind, solar energy. Humidity, precipitation, and topography.
[24] A periscope works on the principle of –
A.
refraction
B.
total internal reflection
C.
diffraction
D.
reflection
Ans:
total internal reflection
Explanation :
Total internal reflection (TIR) is the phenomenon that involves the reflection of the entire incident light off the boundary. Glass prisms can be shaped to produce total internal reflection and as such are employed in binoculars, periscopes, telescopes, and other optical instruments. For the prism used in periscope, the light rays hit the inside surface at an angle greater than the critical angle of 42 and hence they are internally reflected.
[25] A copper disc has a hole. If the disc is heated, the size of the hole -
A.
increases
B.
decreases
C.
No change
D.
first increases and than decreases
Ans:
increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.
Explanation :
The Camphor slowly dissolves in the water lowering the latter’s surface tension in the immediate neighborhood. The stronger pull exerted by the uncontaminated portion of water brings about a movement of the surface and the camphor particles are carried along with it.
[14] Lightning is caused due to –
A.
electric power
B.
electric discharge
C.
electric leak
D.
electric pressure
Ans:
electric discharge
Explanation :
Lightning is a discharge of electrical energy that builds up within a storm. The charges develop because a storm causes air to move around which rubs against itself to generate electrical charges. Eventually the charge increases to a point where the electricity can flow through the air
[15] Sprayer functions on –
A.
Bernouli’s principle
B.
Archeinecle's principle
C.
Pascal's law
D.
Floatation principle
Ans:
Bernouli’s principle
Explanation :
Bernoulli's principle states that as the speed of a moving fluid (liquid or gas) increases, the pressure within the liquid decreases. In the case of a sprayer, when the plunger is pushed in, the air flows at a high velocity through a nozzle, creating a region of low pressure above the metal tube. The higher pressure of the atmospheric air causes the liquid to rise up to the metal tube and come out as spray.
[16] Waves that are required for long distance wireless communication are –
A.
Infrared rays
B.
Ultraviolet rays
C.
Radio waves
D.
Microwaves
Ans:
Radio waves
Explanation :
Wireless communication is the transfer of information between two or more points that are not connected by an electrical conductor. With radio waves distances can be short, such as a few metres for television remote control, or as far as thousands or even millions of kilometres for deep-space radio communications.
[17] Rise of oil a wick is due to –
A.
density of the oil
B.
viscosity of the oil
C.
surface tension of the oil
D.
pressure of the oil
Ans:
surface tension of the oil
Explanation :
The phenomenon of rise or fall of liquid in a capillary tube is called capillarity. Oil rises through a wick due to capillarity. The narrow pores in the threads of a wick act like tiny capillaries, through which oil rises. Capillary action is the result of adhesion and surface tension.
[18] Heat stored in water vapour is –
A.
specific heat
B.
latent heat
C.
absolute heat
D.
relative heat
Ans:
latent heat
Explanation :
Latent heat is the heat released or absorbed by a body or a thermodynamic system during a process that occurs without a change in temperature. A typical example is a change of state of matter, meaning a phase transition such as the melting of ice or the boiling of water. So water vapor which is the end product of evaporated water has latent heat.
[19] The layer of atmosphere used for radio-wave transmission is –
A.
chromosphere
B.
troposphere
C.
ionosphere
D.
stratosphere
Ans:
ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere and 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.
[20] SI unit of luminous intensity is .
A.
lumen
B.
lux
C.
candela
D.
watt
Ans:
candela
Explanation :
Luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd).
[21] A rear-view mirror for driving is –
A.
plain
B.
concave
C.
convex
D.
inverted
Ans:
convex
Explanation :
The kind of mirror used in the rear-view mirror must be convex mirrors, because it creates smaller, yet still upright images. Concave mirrors would create an inverted image and the cars you see are not upside down. Convex mirrors make everything smaller so this allows the driver to see a greater range of things behind him.
[22] The important unit of a microprocessor is –
A.
ALU
B.
array of registers
C.
control unit
D.
All of the above
Ans:
All of the above
Explanation :
The basic units or blocks of a microprocessor are ALU, an array of registers and control unit. A minimal hypothetical microprocessor might only include an arithmetic logic unit (ALU) and a control logic section. Each operation of the ALU sets one or more flags in a status register, which indicate the results of the last operation (zero value, negative number, overflow or others).
[23] Which one of the following is an element of weather?
A.
Wind
B.
Temperature
C.
Humidity
D.
All options are correct
Ans:
All options are correct
Explanation :
There are many elements that make up both the weather and the climate of a geographical location. The most significant of these elements are temperature, atmospheric pressure, wind, solar energy. Humidity, precipitation, and topography.
[24] A periscope works on the principle of –
A.
refraction
B.
total internal reflection
C.
diffraction
D.
reflection
Ans:
total internal reflection
Explanation :
Total internal reflection (TIR) is the phenomenon that involves the reflection of the entire incident light off the boundary. Glass prisms can be shaped to produce total internal reflection and as such are employed in binoculars, periscopes, telescopes, and other optical instruments. For the prism used in periscope, the light rays hit the inside surface at an angle greater than the critical angle of 42 and hence they are internally reflected.
[25] A copper disc has a hole. If the disc is heated, the size of the hole -
A.
increases
B.
decreases
C.
No change
D.
first increases and than decreases
Ans:
increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.
Explanation :
Bernoulli's principle states that as the speed of a moving fluid (liquid or gas) increases, the pressure within the liquid decreases. In the case of a sprayer, when the plunger is pushed in, the air flows at a high velocity through a nozzle, creating a region of low pressure above the metal tube. The higher pressure of the atmospheric air causes the liquid to rise up to the metal tube and come out as spray.
[16] Waves that are required for long distance wireless communication are –
A.
Infrared rays
B.
Ultraviolet rays
C.
Radio waves
D.
Microwaves
Ans:
Radio waves
Explanation :
Wireless communication is the transfer of information between two or more points that are not connected by an electrical conductor. With radio waves distances can be short, such as a few metres for television remote control, or as far as thousands or even millions of kilometres for deep-space radio communications.
[17] Rise of oil a wick is due to –
A.
density of the oil
B.
viscosity of the oil
C.
surface tension of the oil
D.
pressure of the oil
Ans:
surface tension of the oil
Explanation :
The phenomenon of rise or fall of liquid in a capillary tube is called capillarity. Oil rises through a wick due to capillarity. The narrow pores in the threads of a wick act like tiny capillaries, through which oil rises. Capillary action is the result of adhesion and surface tension.
[18] Heat stored in water vapour is –
A.
specific heat
B.
latent heat
C.
absolute heat
D.
relative heat
Ans:
latent heat
Explanation :
Latent heat is the heat released or absorbed by a body or a thermodynamic system during a process that occurs without a change in temperature. A typical example is a change of state of matter, meaning a phase transition such as the melting of ice or the boiling of water. So water vapor which is the end product of evaporated water has latent heat.
[19] The layer of atmosphere used for radio-wave transmission is –
A.
chromosphere
B.
troposphere
C.
ionosphere
D.
stratosphere
Ans:
ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere and 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.
[20] SI unit of luminous intensity is .
A.
lumen
B.
lux
C.
candela
D.
watt
Ans:
candela
Explanation :
Luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd).
[21] A rear-view mirror for driving is –
A.
plain
B.
concave
C.
convex
D.
inverted
Ans:
convex
Explanation :
The kind of mirror used in the rear-view mirror must be convex mirrors, because it creates smaller, yet still upright images. Concave mirrors would create an inverted image and the cars you see are not upside down. Convex mirrors make everything smaller so this allows the driver to see a greater range of things behind him.
[22] The important unit of a microprocessor is –
A.
ALU
B.
array of registers
C.
control unit
D.
All of the above
Ans:
All of the above
Explanation :
The basic units or blocks of a microprocessor are ALU, an array of registers and control unit. A minimal hypothetical microprocessor might only include an arithmetic logic unit (ALU) and a control logic section. Each operation of the ALU sets one or more flags in a status register, which indicate the results of the last operation (zero value, negative number, overflow or others).
[23] Which one of the following is an element of weather?
A.
Wind
B.
Temperature
C.
Humidity
D.
All options are correct
Ans:
All options are correct
Explanation :
There are many elements that make up both the weather and the climate of a geographical location. The most significant of these elements are temperature, atmospheric pressure, wind, solar energy. Humidity, precipitation, and topography.
[24] A periscope works on the principle of –
A.
refraction
B.
total internal reflection
C.
diffraction
D.
reflection
Ans:
total internal reflection
Explanation :
Total internal reflection (TIR) is the phenomenon that involves the reflection of the entire incident light off the boundary. Glass prisms can be shaped to produce total internal reflection and as such are employed in binoculars, periscopes, telescopes, and other optical instruments. For the prism used in periscope, the light rays hit the inside surface at an angle greater than the critical angle of 42 and hence they are internally reflected.
[25] A copper disc has a hole. If the disc is heated, the size of the hole -
A.
increases
B.
decreases
C.
No change
D.
first increases and than decreases
Ans:
increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.
Explanation :
The phenomenon of rise or fall of liquid in a capillary tube is called capillarity. Oil rises through a wick due to capillarity. The narrow pores in the threads of a wick act like tiny capillaries, through which oil rises. Capillary action is the result of adhesion and surface tension.
[18] Heat stored in water vapour is –
A.
specific heat
B.
latent heat
C.
absolute heat
D.
relative heat
Ans:
latent heat
Explanation :
Latent heat is the heat released or absorbed by a body or a thermodynamic system during a process that occurs without a change in temperature. A typical example is a change of state of matter, meaning a phase transition such as the melting of ice or the boiling of water. So water vapor which is the end product of evaporated water has latent heat.
[19] The layer of atmosphere used for radio-wave transmission is –
A.
chromosphere
B.
troposphere
C.
ionosphere
D.
stratosphere
Ans:
ionosphere
Explanation :
The ionosphere is a part of the upper atmosphere and 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.
[20] SI unit of luminous intensity is .
A.
lumen
B.
lux
C.
candela
D.
watt
Ans:
candela
Explanation :
Luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd).
[21] A rear-view mirror for driving is –
A.
plain
B.
concave
C.
convex
D.
inverted
Ans:
convex
Explanation :
The kind of mirror used in the rear-view mirror must be convex mirrors, because it creates smaller, yet still upright images. Concave mirrors would create an inverted image and the cars you see are not upside down. Convex mirrors make everything smaller so this allows the driver to see a greater range of things behind him.
[22] The important unit of a microprocessor is –
A.
ALU
B.
array of registers
C.
control unit
D.
All of the above
Ans:
All of the above
Explanation :
The basic units or blocks of a microprocessor are ALU, an array of registers and control unit. A minimal hypothetical microprocessor might only include an arithmetic logic unit (ALU) and a control logic section. Each operation of the ALU sets one or more flags in a status register, which indicate the results of the last operation (zero value, negative number, overflow or others).
[23] Which one of the following is an element of weather?
A.
Wind
B.
Temperature
C.
Humidity
D.
All options are correct
Ans:
All options are correct
Explanation :
There are many elements that make up both the weather and the climate of a geographical location. The most significant of these elements are temperature, atmospheric pressure, wind, solar energy. Humidity, precipitation, and topography.
[24] A periscope works on the principle of –
A.
refraction
B.
total internal reflection
C.
diffraction
D.
reflection
Ans:
total internal reflection
Explanation :
Total internal reflection (TIR) is the phenomenon that involves the reflection of the entire incident light off the boundary. Glass prisms can be shaped to produce total internal reflection and as such are employed in binoculars, periscopes, telescopes, and other optical instruments. For the prism used in periscope, the light rays hit the inside surface at an angle greater than the critical angle of 42 and hence they are internally reflected.
[25] A copper disc has a hole. If the disc is heated, the size of the hole -
A.
increases
B.
decreases
C.
No change
D.
first increases and than decreases
Ans:
increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.
Explanation :
The ionosphere is a part of the upper atmosphere and 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.
[20] SI unit of luminous intensity is .
A.
lumen
B.
lux
C.
candela
D.
watt
Ans:
candela
Explanation :
Luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd).
[21] A rear-view mirror for driving is –
A.
plain
B.
concave
C.
convex
D.
inverted
Ans:
convex
Explanation :
The kind of mirror used in the rear-view mirror must be convex mirrors, because it creates smaller, yet still upright images. Concave mirrors would create an inverted image and the cars you see are not upside down. Convex mirrors make everything smaller so this allows the driver to see a greater range of things behind him.
[22] The important unit of a microprocessor is –
A.
ALU
B.
array of registers
C.
control unit
D.
All of the above
Ans:
All of the above
Explanation :
The basic units or blocks of a microprocessor are ALU, an array of registers and control unit. A minimal hypothetical microprocessor might only include an arithmetic logic unit (ALU) and a control logic section. Each operation of the ALU sets one or more flags in a status register, which indicate the results of the last operation (zero value, negative number, overflow or others).
[23] Which one of the following is an element of weather?
A.
Wind
B.
Temperature
C.
Humidity
D.
All options are correct
Ans:
All options are correct
Explanation :
There are many elements that make up both the weather and the climate of a geographical location. The most significant of these elements are temperature, atmospheric pressure, wind, solar energy. Humidity, precipitation, and topography.
[24] A periscope works on the principle of –
A.
refraction
B.
total internal reflection
C.
diffraction
D.
reflection
Ans:
total internal reflection
Explanation :
Total internal reflection (TIR) is the phenomenon that involves the reflection of the entire incident light off the boundary. Glass prisms can be shaped to produce total internal reflection and as such are employed in binoculars, periscopes, telescopes, and other optical instruments. For the prism used in periscope, the light rays hit the inside surface at an angle greater than the critical angle of 42 and hence they are internally reflected.
[25] A copper disc has a hole. If the disc is heated, the size of the hole -
A.
increases
B.
decreases
C.
No change
D.
first increases and than decreases
Ans:
increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.
Explanation :
The kind of mirror used in the rear-view mirror must be convex mirrors, because it creates smaller, yet still upright images. Concave mirrors would create an inverted image and the cars you see are not upside down. Convex mirrors make everything smaller so this allows the driver to see a greater range of things behind him.
[22] The important unit of a microprocessor is –
A.
ALU
B.
array of registers
C.
control unit
D.
All of the above
Ans:
All of the above
Explanation :
The basic units or blocks of a microprocessor are ALU, an array of registers and control unit. A minimal hypothetical microprocessor might only include an arithmetic logic unit (ALU) and a control logic section. Each operation of the ALU sets one or more flags in a status register, which indicate the results of the last operation (zero value, negative number, overflow or others).
[23] Which one of the following is an element of weather?
A.
Wind
B.
Temperature
C.
Humidity
D.
All options are correct
Ans:
All options are correct
Explanation :
There are many elements that make up both the weather and the climate of a geographical location. The most significant of these elements are temperature, atmospheric pressure, wind, solar energy. Humidity, precipitation, and topography.
[24] A periscope works on the principle of –
A.
refraction
B.
total internal reflection
C.
diffraction
D.
reflection
Ans:
total internal reflection
Explanation :
Total internal reflection (TIR) is the phenomenon that involves the reflection of the entire incident light off the boundary. Glass prisms can be shaped to produce total internal reflection and as such are employed in binoculars, periscopes, telescopes, and other optical instruments. For the prism used in periscope, the light rays hit the inside surface at an angle greater than the critical angle of 42 and hence they are internally reflected.
[25] A copper disc has a hole. If the disc is heated, the size of the hole -
A.
increases
B.
decreases
C.
No change
D.
first increases and than decreases
Ans:
increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.
Explanation :
There are many elements that make up both the weather and the climate of a geographical location. The most significant of these elements are temperature, atmospheric pressure, wind, solar energy. Humidity, precipitation, and topography.
[24] A periscope works on the principle of –
A.
refraction
B.
total internal reflection
C.
diffraction
D.
reflection
Ans:
total internal reflection
Explanation :
Total internal reflection (TIR) is the phenomenon that involves the reflection of the entire incident light off the boundary. Glass prisms can be shaped to produce total internal reflection and as such are employed in binoculars, periscopes, telescopes, and other optical instruments. For the prism used in periscope, the light rays hit the inside surface at an angle greater than the critical angle of 42 and hence they are internally reflected.
[25] A copper disc has a hole. If the disc is heated, the size of the hole -
A.
increases
B.
decreases
C.
No change
D.
first increases and than decreases
Ans:
increases
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.
Explanation :
When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.