[1] The freezing point of fresh water is -
A.
4°C
B.
3°C
C.
5°C
D.
0°C
Ans:
0°C
Explanation :
The freezing point of water is the temperature at which water changes phase from a liquid to a solid. Under normal conditions, ordinary water freezes at 0°C, or 32°F. The temperature may be lower if supercooling occurs or if there are impurities present in the water which could cause freezing point depression to occur.
[2] The unit of noise pollution (level) is –
A.
decibel
B.
decimal
C.
ppm
D.
None of these
Ans:
decibel
Explanation :
Noise pollution refers to any unpleasant, damaging or irritating noise that has the potential to harm people, wildlife or the environment. The decibel (dB) is the main unit used to measure the intensity or loudness of sounds. A sound can also be measured by its pitch, which is the frequency of sound vibrations per second.
[3] The boiling point of water decreases at higher altitudes is due to –
A.
low temperature
B.
low atmospheric pressure
C.
high temperature
D.
high atmospheric pressure
Ans:
low atmospheric pressure
Explanation :
At higher altitudes, the air pressure is decreased, which forces water's boiling point to lower. The air pressure decreases with altitude because of the decrease in the density of air. The lowered boiling point of water requires an increase in cooking times or temperature.
[4] The reactivity of an ionic compound element is explained as its tendency to attain noble gas configuration. How do the elements do so?
A.
Lose electrons
B.
Gain electrons
C.
Both are correct
D.
Both are incorrect
Ans:
Both are correct
Explanation :
The reactivity of elements is explained as their tendency to attain a completely filled outer shell. This is called as having attained noble gas configuration. Once noble gas configuration is reached, the elements lose their reactivity.
[5] A water tank appears shallower when it is viewed from top due to –
A.
rectilinear propagation of light
B.
reflection
C.
total internal reflection
D.
refraction
Ans:
refraction
Explanation :
This phenomenon is because of refraction of light. The lines of sight intersect at a higher position than where the actual rays originated. This causes the water to appear shallower than it really is. The depth that the water appears to be when viewed from above is known as the apparent depth.
[6] For a ray of light to suffer total internal reflection it has to pass from –
A.
glass to water
B.
water to glass
C.
air to water
D.
air to glass
Ans:
air to water
Explanation :
Total internal reflection is an optical phenomenon that happens when a ray of light strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface.
[7] For which of the following substances, the resistance decreases with increase in temperature?
A.
Pure silicon
B.
Copper
C.
Nichrome
D.
Platinum
Ans:
Nichrome
Explanation :
Nichrome has high resistance and it is called a resistor.
[8] A solid needle placed horizontally on the surface of the water floats due to –
A.
capillary action
B.
water pressure
C.
surface tension of water
D.
viscosity of water
Ans:
surface tension of water
Explanation :
A solid needle placed horizontally on the surface of water floats due to surface tension of water.
[9] The first equation of motion gives the relation between :
A.
Position and time
B.
Position and Velocity
C.
Velocity and time
D.
Velocity and acceleration
Ans:
Velocity and time
Explanation :
The equation v = u + at is called Newton's first equation of motion, where, u = Initial velocity, v = Final velocity, a = acceleration and t = time.
[10] What is the minimum distance (in metres) required to hear an echo?
A.
10
B.
13
C.
17
D.
21
Ans:
17
Explanation :
The human ear cannot distinguish echo from the original direct sound if the delay is less than 1/15 of a second. The velocity of sound in dry air is approximately 343 m/s at a temperature of 25⁰C.
[11] The intensity ratio of waves is 25:9. What is the ratio of their amplitudes?
A.
50 : 18
B.
25 : 9
C.
3 : 5
D.
5 : 3
Ans:
5 : 3
Explanation :
In general, the intensity of a wave is proportional to the square of its amplitude. This has an important implication: relative intensity can be obtained by squaring relative amplitude. So if the intensity ratio is 25:9, the amplitude ratio will be 5:3.
[12] Which of these travels in glass with minimum velocity?
A.
red light
B.
violet light
C.
green light
D.
yellow light
Ans:
violet light
Explanation :
Red light has a longer wavelength than violet light and the other colours of visible light have intermediate wavelengths. As light passes from air into glass, there is reduction of velocity. Due to longer wave-lengths, red waves travel fastest and is refracted the least, while violet waves travel the slowest and is refracted the most.
[13] The phenomenon which causes mirage is –
A.
Interference
B.
Diffraction
C.
Polarisation
D.
Total internal reflection
Ans:
Total internal reflection
Explanation :
Mirage is caused by total internal reflection in deserts where due to heating of the earth, refractive index of air near the surface of earth becomes lesser than above it. A ray of light coming from a distant object gets refracted from a denser to a rarer medium.
[14] Which of the following is indicated by the colour of a star?
A.
weight
B.
distance
C.
temperature
D.
size
Ans:
temperature
Explanation :
Colour is caused by the temperature of the surface of the star. A star approximates the behavior of a black body radiator. As a black body gets hotter its color changes. Small stars are cool (less than 3000°C) with a reddish appearance, whereas big heavy stars are hot (over 30,000°C), and have a bluish glow.
[15] For which one of the following, 'Diodes' are generally used for?
A.
Rectification
B.
Amplification
C.
Modulation
D.
Filtration
Ans:
Rectification
Explanation :
In electronics, a diode is an electronic device that allows current to flow in one direction only. It is mainly used as a rectifier diode that lets electrical current flow in only one direction and is mainly used for power supply operation. Rectifier diodes are used for changing alternating current into direct current.
[16] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in –
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[17] Which one among the following components is used as an amplifying device?
A.
Transformer
B.
Diode
C.
Capacitor
D.
Transistor
Ans:
Transistor
Explanation :
An amplifier is an electronic device that increases the voltage, current, or power of a signal. Generally transistors are active devices that can be used with discrete components to amplify voltage, power or both depending upon the configuration.
[18] The commonly used coolant in refrigerators is –
A.
Ammonia
B.
Nitrogen
C.
Freon
D.
Oxygen
Ans:
Freon
Explanation :
Modem refrigerators usually use a refrigerant called FIFC-134a (1,1,1,2-Tetrafluoroethane), which does not deplete the ozone layer, instead of Freon. Freon used to be the most common refrigerant till the 1980s; however, its use has declined since
[19] The term ‘Higgs Boson’ is associated with -
A.
Nano Technology
B.
Oncology
C.
God Particle
D.
Stem Cell Research
Ans:
God Particle
Explanation :
The Higgs boson is an elementary particle in the Standard Model of particle physics. That is often referred to as the “God particle” in popular media outside the scientific community.
[20] Kilowatt-hour (KWH) is the unit of -
A.
power
B.
resistance
C.
resistivity
D.
energy
Ans:
energy
Explanation :
The kilowatt hour (symbol kWh, kW⋅h or kW h) is a unit of energy equal to 3.6 mega joules. If the energy is being transmitted or used at a constant rate (power) over a period of time, the total energy in kilowatt hours is the power in kilowatts multiplied by the time in hours.
[21] Major portion of the earth’s crust is mainly constituted by -
A.
Oxygen and Iron
B.
Oxygen and Silicon
C.
Silicon and Iron
D.
Silicon and Aluminium
Ans:
Oxygen and Silicon
Explanation :
Oxygen is the most abundant element in the earth’s crust, comprising 46.6% or the crust by weight. Silicon 28%, aluminum 8.2%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium, 2.0%, and titanium 0.61% also comprise the crust.
[22] The mirror used by ENT specialist is:
A.
Plane mirror
B.
Concave mirror
C.
Convex mirror
D.
None of these
Ans:
Concave mirror
Explanation :
To see the inner part of ear and other parts, E.N.T doctors use a concave mirror. When the rays of light falls on reflecting surface of concave mirror, that time Concave mirror concentrate those all the rays at its focus.
[23] Fibre optics work on the principle of -
A.
scattering of light
B.
total internal absorption
C.
total internal reflection
D.
option rotation
Ans:
total internal reflection
Explanation :
An optical fibre is a cylindrical dielectric waveguide (non-conducting waveguide) that transmits light along its axis, by the process of total internal reflection.
[24] The reverse effect of X-ray emission is –
A.
Raman effect
B.
Compton effect
C.
Zeeman effect
D.
Photoelectric
Ans:
Photoelectric
Explanation :
When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
[25] The group of solar cells joined together in a definite pattern is called a –
A.
Battery
B.
Solar heater
C.
Solar cooker
D.
Solar cell panel
Ans:
Solar cell panel
Explanation :
A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a `solar cell panel'. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.
Explanation :
The freezing point of water is the temperature at which water changes phase from a liquid to a solid. Under normal conditions, ordinary water freezes at 0°C, or 32°F. The temperature may be lower if supercooling occurs or if there are impurities present in the water which could cause freezing point depression to occur.
[2] The unit of noise pollution (level) is –
A.
decibel
B.
decimal
C.
ppm
D.
None of these
Ans:
decibel
Explanation :
Noise pollution refers to any unpleasant, damaging or irritating noise that has the potential to harm people, wildlife or the environment. The decibel (dB) is the main unit used to measure the intensity or loudness of sounds. A sound can also be measured by its pitch, which is the frequency of sound vibrations per second.
[3] The boiling point of water decreases at higher altitudes is due to –
A.
low temperature
B.
low atmospheric pressure
C.
high temperature
D.
high atmospheric pressure
Ans:
low atmospheric pressure
Explanation :
At higher altitudes, the air pressure is decreased, which forces water's boiling point to lower. The air pressure decreases with altitude because of the decrease in the density of air. The lowered boiling point of water requires an increase in cooking times or temperature.
[4] The reactivity of an ionic compound element is explained as its tendency to attain noble gas configuration. How do the elements do so?
A.
Lose electrons
B.
Gain electrons
C.
Both are correct
D.
Both are incorrect
Ans:
Both are correct
Explanation :
The reactivity of elements is explained as their tendency to attain a completely filled outer shell. This is called as having attained noble gas configuration. Once noble gas configuration is reached, the elements lose their reactivity.
[5] A water tank appears shallower when it is viewed from top due to –
A.
rectilinear propagation of light
B.
reflection
C.
total internal reflection
D.
refraction
Ans:
refraction
Explanation :
This phenomenon is because of refraction of light. The lines of sight intersect at a higher position than where the actual rays originated. This causes the water to appear shallower than it really is. The depth that the water appears to be when viewed from above is known as the apparent depth.
[6] For a ray of light to suffer total internal reflection it has to pass from –
A.
glass to water
B.
water to glass
C.
air to water
D.
air to glass
Ans:
air to water
Explanation :
Total internal reflection is an optical phenomenon that happens when a ray of light strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface.
[7] For which of the following substances, the resistance decreases with increase in temperature?
A.
Pure silicon
B.
Copper
C.
Nichrome
D.
Platinum
Ans:
Nichrome
Explanation :
Nichrome has high resistance and it is called a resistor.
[8] A solid needle placed horizontally on the surface of the water floats due to –
A.
capillary action
B.
water pressure
C.
surface tension of water
D.
viscosity of water
Ans:
surface tension of water
Explanation :
A solid needle placed horizontally on the surface of water floats due to surface tension of water.
[9] The first equation of motion gives the relation between :
A.
Position and time
B.
Position and Velocity
C.
Velocity and time
D.
Velocity and acceleration
Ans:
Velocity and time
Explanation :
The equation v = u + at is called Newton's first equation of motion, where, u = Initial velocity, v = Final velocity, a = acceleration and t = time.
[10] What is the minimum distance (in metres) required to hear an echo?
A.
10
B.
13
C.
17
D.
21
Ans:
17
Explanation :
The human ear cannot distinguish echo from the original direct sound if the delay is less than 1/15 of a second. The velocity of sound in dry air is approximately 343 m/s at a temperature of 25⁰C.
[11] The intensity ratio of waves is 25:9. What is the ratio of their amplitudes?
A.
50 : 18
B.
25 : 9
C.
3 : 5
D.
5 : 3
Ans:
5 : 3
Explanation :
In general, the intensity of a wave is proportional to the square of its amplitude. This has an important implication: relative intensity can be obtained by squaring relative amplitude. So if the intensity ratio is 25:9, the amplitude ratio will be 5:3.
[12] Which of these travels in glass with minimum velocity?
A.
red light
B.
violet light
C.
green light
D.
yellow light
Ans:
violet light
Explanation :
Red light has a longer wavelength than violet light and the other colours of visible light have intermediate wavelengths. As light passes from air into glass, there is reduction of velocity. Due to longer wave-lengths, red waves travel fastest and is refracted the least, while violet waves travel the slowest and is refracted the most.
[13] The phenomenon which causes mirage is –
A.
Interference
B.
Diffraction
C.
Polarisation
D.
Total internal reflection
Ans:
Total internal reflection
Explanation :
Mirage is caused by total internal reflection in deserts where due to heating of the earth, refractive index of air near the surface of earth becomes lesser than above it. A ray of light coming from a distant object gets refracted from a denser to a rarer medium.
[14] Which of the following is indicated by the colour of a star?
A.
weight
B.
distance
C.
temperature
D.
size
Ans:
temperature
Explanation :
Colour is caused by the temperature of the surface of the star. A star approximates the behavior of a black body radiator. As a black body gets hotter its color changes. Small stars are cool (less than 3000°C) with a reddish appearance, whereas big heavy stars are hot (over 30,000°C), and have a bluish glow.
[15] For which one of the following, 'Diodes' are generally used for?
A.
Rectification
B.
Amplification
C.
Modulation
D.
Filtration
Ans:
Rectification
Explanation :
In electronics, a diode is an electronic device that allows current to flow in one direction only. It is mainly used as a rectifier diode that lets electrical current flow in only one direction and is mainly used for power supply operation. Rectifier diodes are used for changing alternating current into direct current.
[16] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in –
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[17] Which one among the following components is used as an amplifying device?
A.
Transformer
B.
Diode
C.
Capacitor
D.
Transistor
Ans:
Transistor
Explanation :
An amplifier is an electronic device that increases the voltage, current, or power of a signal. Generally transistors are active devices that can be used with discrete components to amplify voltage, power or both depending upon the configuration.
[18] The commonly used coolant in refrigerators is –
A.
Ammonia
B.
Nitrogen
C.
Freon
D.
Oxygen
Ans:
Freon
Explanation :
Modem refrigerators usually use a refrigerant called FIFC-134a (1,1,1,2-Tetrafluoroethane), which does not deplete the ozone layer, instead of Freon. Freon used to be the most common refrigerant till the 1980s; however, its use has declined since
[19] The term ‘Higgs Boson’ is associated with -
A.
Nano Technology
B.
Oncology
C.
God Particle
D.
Stem Cell Research
Ans:
God Particle
Explanation :
The Higgs boson is an elementary particle in the Standard Model of particle physics. That is often referred to as the “God particle” in popular media outside the scientific community.
[20] Kilowatt-hour (KWH) is the unit of -
A.
power
B.
resistance
C.
resistivity
D.
energy
Ans:
energy
Explanation :
The kilowatt hour (symbol kWh, kW⋅h or kW h) is a unit of energy equal to 3.6 mega joules. If the energy is being transmitted or used at a constant rate (power) over a period of time, the total energy in kilowatt hours is the power in kilowatts multiplied by the time in hours.
[21] Major portion of the earth’s crust is mainly constituted by -
A.
Oxygen and Iron
B.
Oxygen and Silicon
C.
Silicon and Iron
D.
Silicon and Aluminium
Ans:
Oxygen and Silicon
Explanation :
Oxygen is the most abundant element in the earth’s crust, comprising 46.6% or the crust by weight. Silicon 28%, aluminum 8.2%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium, 2.0%, and titanium 0.61% also comprise the crust.
[22] The mirror used by ENT specialist is:
A.
Plane mirror
B.
Concave mirror
C.
Convex mirror
D.
None of these
Ans:
Concave mirror
Explanation :
To see the inner part of ear and other parts, E.N.T doctors use a concave mirror. When the rays of light falls on reflecting surface of concave mirror, that time Concave mirror concentrate those all the rays at its focus.
[23] Fibre optics work on the principle of -
A.
scattering of light
B.
total internal absorption
C.
total internal reflection
D.
option rotation
Ans:
total internal reflection
Explanation :
An optical fibre is a cylindrical dielectric waveguide (non-conducting waveguide) that transmits light along its axis, by the process of total internal reflection.
[24] The reverse effect of X-ray emission is –
A.
Raman effect
B.
Compton effect
C.
Zeeman effect
D.
Photoelectric
Ans:
Photoelectric
Explanation :
When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
[25] The group of solar cells joined together in a definite pattern is called a –
A.
Battery
B.
Solar heater
C.
Solar cooker
D.
Solar cell panel
Ans:
Solar cell panel
Explanation :
A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a `solar cell panel'. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.
Explanation :
At higher altitudes, the air pressure is decreased, which forces water's boiling point to lower. The air pressure decreases with altitude because of the decrease in the density of air. The lowered boiling point of water requires an increase in cooking times or temperature.
[4] The reactivity of an ionic compound element is explained as its tendency to attain noble gas configuration. How do the elements do so?
A.
Lose electrons
B.
Gain electrons
C.
Both are correct
D.
Both are incorrect
Ans:
Both are correct
Explanation :
The reactivity of elements is explained as their tendency to attain a completely filled outer shell. This is called as having attained noble gas configuration. Once noble gas configuration is reached, the elements lose their reactivity.
[5] A water tank appears shallower when it is viewed from top due to –
A.
rectilinear propagation of light
B.
reflection
C.
total internal reflection
D.
refraction
Ans:
refraction
Explanation :
This phenomenon is because of refraction of light. The lines of sight intersect at a higher position than where the actual rays originated. This causes the water to appear shallower than it really is. The depth that the water appears to be when viewed from above is known as the apparent depth.
[6] For a ray of light to suffer total internal reflection it has to pass from –
A.
glass to water
B.
water to glass
C.
air to water
D.
air to glass
Ans:
air to water
Explanation :
Total internal reflection is an optical phenomenon that happens when a ray of light strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface.
[7] For which of the following substances, the resistance decreases with increase in temperature?
A.
Pure silicon
B.
Copper
C.
Nichrome
D.
Platinum
Ans:
Nichrome
Explanation :
Nichrome has high resistance and it is called a resistor.
[8] A solid needle placed horizontally on the surface of the water floats due to –
A.
capillary action
B.
water pressure
C.
surface tension of water
D.
viscosity of water
Ans:
surface tension of water
Explanation :
A solid needle placed horizontally on the surface of water floats due to surface tension of water.
[9] The first equation of motion gives the relation between :
A.
Position and time
B.
Position and Velocity
C.
Velocity and time
D.
Velocity and acceleration
Ans:
Velocity and time
Explanation :
The equation v = u + at is called Newton's first equation of motion, where, u = Initial velocity, v = Final velocity, a = acceleration and t = time.
[10] What is the minimum distance (in metres) required to hear an echo?
A.
10
B.
13
C.
17
D.
21
Ans:
17
Explanation :
The human ear cannot distinguish echo from the original direct sound if the delay is less than 1/15 of a second. The velocity of sound in dry air is approximately 343 m/s at a temperature of 25⁰C.
[11] The intensity ratio of waves is 25:9. What is the ratio of their amplitudes?
A.
50 : 18
B.
25 : 9
C.
3 : 5
D.
5 : 3
Ans:
5 : 3
Explanation :
In general, the intensity of a wave is proportional to the square of its amplitude. This has an important implication: relative intensity can be obtained by squaring relative amplitude. So if the intensity ratio is 25:9, the amplitude ratio will be 5:3.
[12] Which of these travels in glass with minimum velocity?
A.
red light
B.
violet light
C.
green light
D.
yellow light
Ans:
violet light
Explanation :
Red light has a longer wavelength than violet light and the other colours of visible light have intermediate wavelengths. As light passes from air into glass, there is reduction of velocity. Due to longer wave-lengths, red waves travel fastest and is refracted the least, while violet waves travel the slowest and is refracted the most.
[13] The phenomenon which causes mirage is –
A.
Interference
B.
Diffraction
C.
Polarisation
D.
Total internal reflection
Ans:
Total internal reflection
Explanation :
Mirage is caused by total internal reflection in deserts where due to heating of the earth, refractive index of air near the surface of earth becomes lesser than above it. A ray of light coming from a distant object gets refracted from a denser to a rarer medium.
[14] Which of the following is indicated by the colour of a star?
A.
weight
B.
distance
C.
temperature
D.
size
Ans:
temperature
Explanation :
Colour is caused by the temperature of the surface of the star. A star approximates the behavior of a black body radiator. As a black body gets hotter its color changes. Small stars are cool (less than 3000°C) with a reddish appearance, whereas big heavy stars are hot (over 30,000°C), and have a bluish glow.
[15] For which one of the following, 'Diodes' are generally used for?
A.
Rectification
B.
Amplification
C.
Modulation
D.
Filtration
Ans:
Rectification
Explanation :
In electronics, a diode is an electronic device that allows current to flow in one direction only. It is mainly used as a rectifier diode that lets electrical current flow in only one direction and is mainly used for power supply operation. Rectifier diodes are used for changing alternating current into direct current.
[16] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in –
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[17] Which one among the following components is used as an amplifying device?
A.
Transformer
B.
Diode
C.
Capacitor
D.
Transistor
Ans:
Transistor
Explanation :
An amplifier is an electronic device that increases the voltage, current, or power of a signal. Generally transistors are active devices that can be used with discrete components to amplify voltage, power or both depending upon the configuration.
[18] The commonly used coolant in refrigerators is –
A.
Ammonia
B.
Nitrogen
C.
Freon
D.
Oxygen
Ans:
Freon
Explanation :
Modem refrigerators usually use a refrigerant called FIFC-134a (1,1,1,2-Tetrafluoroethane), which does not deplete the ozone layer, instead of Freon. Freon used to be the most common refrigerant till the 1980s; however, its use has declined since
[19] The term ‘Higgs Boson’ is associated with -
A.
Nano Technology
B.
Oncology
C.
God Particle
D.
Stem Cell Research
Ans:
God Particle
Explanation :
The Higgs boson is an elementary particle in the Standard Model of particle physics. That is often referred to as the “God particle” in popular media outside the scientific community.
[20] Kilowatt-hour (KWH) is the unit of -
A.
power
B.
resistance
C.
resistivity
D.
energy
Ans:
energy
Explanation :
The kilowatt hour (symbol kWh, kW⋅h or kW h) is a unit of energy equal to 3.6 mega joules. If the energy is being transmitted or used at a constant rate (power) over a period of time, the total energy in kilowatt hours is the power in kilowatts multiplied by the time in hours.
[21] Major portion of the earth’s crust is mainly constituted by -
A.
Oxygen and Iron
B.
Oxygen and Silicon
C.
Silicon and Iron
D.
Silicon and Aluminium
Ans:
Oxygen and Silicon
Explanation :
Oxygen is the most abundant element in the earth’s crust, comprising 46.6% or the crust by weight. Silicon 28%, aluminum 8.2%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium, 2.0%, and titanium 0.61% also comprise the crust.
[22] The mirror used by ENT specialist is:
A.
Plane mirror
B.
Concave mirror
C.
Convex mirror
D.
None of these
Ans:
Concave mirror
Explanation :
To see the inner part of ear and other parts, E.N.T doctors use a concave mirror. When the rays of light falls on reflecting surface of concave mirror, that time Concave mirror concentrate those all the rays at its focus.
[23] Fibre optics work on the principle of -
A.
scattering of light
B.
total internal absorption
C.
total internal reflection
D.
option rotation
Ans:
total internal reflection
Explanation :
An optical fibre is a cylindrical dielectric waveguide (non-conducting waveguide) that transmits light along its axis, by the process of total internal reflection.
[24] The reverse effect of X-ray emission is –
A.
Raman effect
B.
Compton effect
C.
Zeeman effect
D.
Photoelectric
Ans:
Photoelectric
Explanation :
When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
[25] The group of solar cells joined together in a definite pattern is called a –
A.
Battery
B.
Solar heater
C.
Solar cooker
D.
Solar cell panel
Ans:
Solar cell panel
Explanation :
A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a `solar cell panel'. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.
Explanation :
This phenomenon is because of refraction of light. The lines of sight intersect at a higher position than where the actual rays originated. This causes the water to appear shallower than it really is. The depth that the water appears to be when viewed from above is known as the apparent depth.
[6] For a ray of light to suffer total internal reflection it has to pass from –
A.
glass to water
B.
water to glass
C.
air to water
D.
air to glass
Ans:
air to water
Explanation :
Total internal reflection is an optical phenomenon that happens when a ray of light strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface.
[7] For which of the following substances, the resistance decreases with increase in temperature?
A.
Pure silicon
B.
Copper
C.
Nichrome
D.
Platinum
Ans:
Nichrome
Explanation :
Nichrome has high resistance and it is called a resistor.
[8] A solid needle placed horizontally on the surface of the water floats due to –
A.
capillary action
B.
water pressure
C.
surface tension of water
D.
viscosity of water
Ans:
surface tension of water
Explanation :
A solid needle placed horizontally on the surface of water floats due to surface tension of water.
[9] The first equation of motion gives the relation between :
A.
Position and time
B.
Position and Velocity
C.
Velocity and time
D.
Velocity and acceleration
Ans:
Velocity and time
Explanation :
The equation v = u + at is called Newton's first equation of motion, where, u = Initial velocity, v = Final velocity, a = acceleration and t = time.
[10] What is the minimum distance (in metres) required to hear an echo?
A.
10
B.
13
C.
17
D.
21
Ans:
17
Explanation :
The human ear cannot distinguish echo from the original direct sound if the delay is less than 1/15 of a second. The velocity of sound in dry air is approximately 343 m/s at a temperature of 25⁰C.
[11] The intensity ratio of waves is 25:9. What is the ratio of their amplitudes?
A.
50 : 18
B.
25 : 9
C.
3 : 5
D.
5 : 3
Ans:
5 : 3
Explanation :
In general, the intensity of a wave is proportional to the square of its amplitude. This has an important implication: relative intensity can be obtained by squaring relative amplitude. So if the intensity ratio is 25:9, the amplitude ratio will be 5:3.
[12] Which of these travels in glass with minimum velocity?
A.
red light
B.
violet light
C.
green light
D.
yellow light
Ans:
violet light
Explanation :
Red light has a longer wavelength than violet light and the other colours of visible light have intermediate wavelengths. As light passes from air into glass, there is reduction of velocity. Due to longer wave-lengths, red waves travel fastest and is refracted the least, while violet waves travel the slowest and is refracted the most.
[13] The phenomenon which causes mirage is –
A.
Interference
B.
Diffraction
C.
Polarisation
D.
Total internal reflection
Ans:
Total internal reflection
Explanation :
Mirage is caused by total internal reflection in deserts where due to heating of the earth, refractive index of air near the surface of earth becomes lesser than above it. A ray of light coming from a distant object gets refracted from a denser to a rarer medium.
[14] Which of the following is indicated by the colour of a star?
A.
weight
B.
distance
C.
temperature
D.
size
Ans:
temperature
Explanation :
Colour is caused by the temperature of the surface of the star. A star approximates the behavior of a black body radiator. As a black body gets hotter its color changes. Small stars are cool (less than 3000°C) with a reddish appearance, whereas big heavy stars are hot (over 30,000°C), and have a bluish glow.
[15] For which one of the following, 'Diodes' are generally used for?
A.
Rectification
B.
Amplification
C.
Modulation
D.
Filtration
Ans:
Rectification
Explanation :
In electronics, a diode is an electronic device that allows current to flow in one direction only. It is mainly used as a rectifier diode that lets electrical current flow in only one direction and is mainly used for power supply operation. Rectifier diodes are used for changing alternating current into direct current.
[16] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in –
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[17] Which one among the following components is used as an amplifying device?
A.
Transformer
B.
Diode
C.
Capacitor
D.
Transistor
Ans:
Transistor
Explanation :
An amplifier is an electronic device that increases the voltage, current, or power of a signal. Generally transistors are active devices that can be used with discrete components to amplify voltage, power or both depending upon the configuration.
[18] The commonly used coolant in refrigerators is –
A.
Ammonia
B.
Nitrogen
C.
Freon
D.
Oxygen
Ans:
Freon
Explanation :
Modem refrigerators usually use a refrigerant called FIFC-134a (1,1,1,2-Tetrafluoroethane), which does not deplete the ozone layer, instead of Freon. Freon used to be the most common refrigerant till the 1980s; however, its use has declined since
[19] The term ‘Higgs Boson’ is associated with -
A.
Nano Technology
B.
Oncology
C.
God Particle
D.
Stem Cell Research
Ans:
God Particle
Explanation :
The Higgs boson is an elementary particle in the Standard Model of particle physics. That is often referred to as the “God particle” in popular media outside the scientific community.
[20] Kilowatt-hour (KWH) is the unit of -
A.
power
B.
resistance
C.
resistivity
D.
energy
Ans:
energy
Explanation :
The kilowatt hour (symbol kWh, kW⋅h or kW h) is a unit of energy equal to 3.6 mega joules. If the energy is being transmitted or used at a constant rate (power) over a period of time, the total energy in kilowatt hours is the power in kilowatts multiplied by the time in hours.
[21] Major portion of the earth’s crust is mainly constituted by -
A.
Oxygen and Iron
B.
Oxygen and Silicon
C.
Silicon and Iron
D.
Silicon and Aluminium
Ans:
Oxygen and Silicon
Explanation :
Oxygen is the most abundant element in the earth’s crust, comprising 46.6% or the crust by weight. Silicon 28%, aluminum 8.2%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium, 2.0%, and titanium 0.61% also comprise the crust.
[22] The mirror used by ENT specialist is:
A.
Plane mirror
B.
Concave mirror
C.
Convex mirror
D.
None of these
Ans:
Concave mirror
Explanation :
To see the inner part of ear and other parts, E.N.T doctors use a concave mirror. When the rays of light falls on reflecting surface of concave mirror, that time Concave mirror concentrate those all the rays at its focus.
[23] Fibre optics work on the principle of -
A.
scattering of light
B.
total internal absorption
C.
total internal reflection
D.
option rotation
Ans:
total internal reflection
Explanation :
An optical fibre is a cylindrical dielectric waveguide (non-conducting waveguide) that transmits light along its axis, by the process of total internal reflection.
[24] The reverse effect of X-ray emission is –
A.
Raman effect
B.
Compton effect
C.
Zeeman effect
D.
Photoelectric
Ans:
Photoelectric
Explanation :
When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
[25] The group of solar cells joined together in a definite pattern is called a –
A.
Battery
B.
Solar heater
C.
Solar cooker
D.
Solar cell panel
Ans:
Solar cell panel
Explanation :
A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a `solar cell panel'. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.
Explanation :
Nichrome has high resistance and it is called a resistor.
[8] A solid needle placed horizontally on the surface of the water floats due to –
A.
capillary action
B.
water pressure
C.
surface tension of water
D.
viscosity of water
Ans:
surface tension of water
Explanation :
A solid needle placed horizontally on the surface of water floats due to surface tension of water.
[9] The first equation of motion gives the relation between :
A.
Position and time
B.
Position and Velocity
C.
Velocity and time
D.
Velocity and acceleration
Ans:
Velocity and time
Explanation :
The equation v = u + at is called Newton's first equation of motion, where, u = Initial velocity, v = Final velocity, a = acceleration and t = time.
[10] What is the minimum distance (in metres) required to hear an echo?
A.
10
B.
13
C.
17
D.
21
Ans:
17
Explanation :
The human ear cannot distinguish echo from the original direct sound if the delay is less than 1/15 of a second. The velocity of sound in dry air is approximately 343 m/s at a temperature of 25⁰C.
[11] The intensity ratio of waves is 25:9. What is the ratio of their amplitudes?
A.
50 : 18
B.
25 : 9
C.
3 : 5
D.
5 : 3
Ans:
5 : 3
Explanation :
In general, the intensity of a wave is proportional to the square of its amplitude. This has an important implication: relative intensity can be obtained by squaring relative amplitude. So if the intensity ratio is 25:9, the amplitude ratio will be 5:3.
[12] Which of these travels in glass with minimum velocity?
A.
red light
B.
violet light
C.
green light
D.
yellow light
Ans:
violet light
Explanation :
Red light has a longer wavelength than violet light and the other colours of visible light have intermediate wavelengths. As light passes from air into glass, there is reduction of velocity. Due to longer wave-lengths, red waves travel fastest and is refracted the least, while violet waves travel the slowest and is refracted the most.
[13] The phenomenon which causes mirage is –
A.
Interference
B.
Diffraction
C.
Polarisation
D.
Total internal reflection
Ans:
Total internal reflection
Explanation :
Mirage is caused by total internal reflection in deserts where due to heating of the earth, refractive index of air near the surface of earth becomes lesser than above it. A ray of light coming from a distant object gets refracted from a denser to a rarer medium.
[14] Which of the following is indicated by the colour of a star?
A.
weight
B.
distance
C.
temperature
D.
size
Ans:
temperature
Explanation :
Colour is caused by the temperature of the surface of the star. A star approximates the behavior of a black body radiator. As a black body gets hotter its color changes. Small stars are cool (less than 3000°C) with a reddish appearance, whereas big heavy stars are hot (over 30,000°C), and have a bluish glow.
[15] For which one of the following, 'Diodes' are generally used for?
A.
Rectification
B.
Amplification
C.
Modulation
D.
Filtration
Ans:
Rectification
Explanation :
In electronics, a diode is an electronic device that allows current to flow in one direction only. It is mainly used as a rectifier diode that lets electrical current flow in only one direction and is mainly used for power supply operation. Rectifier diodes are used for changing alternating current into direct current.
[16] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in –
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[17] Which one among the following components is used as an amplifying device?
A.
Transformer
B.
Diode
C.
Capacitor
D.
Transistor
Ans:
Transistor
Explanation :
An amplifier is an electronic device that increases the voltage, current, or power of a signal. Generally transistors are active devices that can be used with discrete components to amplify voltage, power or both depending upon the configuration.
[18] The commonly used coolant in refrigerators is –
A.
Ammonia
B.
Nitrogen
C.
Freon
D.
Oxygen
Ans:
Freon
Explanation :
Modem refrigerators usually use a refrigerant called FIFC-134a (1,1,1,2-Tetrafluoroethane), which does not deplete the ozone layer, instead of Freon. Freon used to be the most common refrigerant till the 1980s; however, its use has declined since
[19] The term ‘Higgs Boson’ is associated with -
A.
Nano Technology
B.
Oncology
C.
God Particle
D.
Stem Cell Research
Ans:
God Particle
Explanation :
The Higgs boson is an elementary particle in the Standard Model of particle physics. That is often referred to as the “God particle” in popular media outside the scientific community.
[20] Kilowatt-hour (KWH) is the unit of -
A.
power
B.
resistance
C.
resistivity
D.
energy
Ans:
energy
Explanation :
The kilowatt hour (symbol kWh, kW⋅h or kW h) is a unit of energy equal to 3.6 mega joules. If the energy is being transmitted or used at a constant rate (power) over a period of time, the total energy in kilowatt hours is the power in kilowatts multiplied by the time in hours.
[21] Major portion of the earth’s crust is mainly constituted by -
A.
Oxygen and Iron
B.
Oxygen and Silicon
C.
Silicon and Iron
D.
Silicon and Aluminium
Ans:
Oxygen and Silicon
Explanation :
Oxygen is the most abundant element in the earth’s crust, comprising 46.6% or the crust by weight. Silicon 28%, aluminum 8.2%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium, 2.0%, and titanium 0.61% also comprise the crust.
[22] The mirror used by ENT specialist is:
A.
Plane mirror
B.
Concave mirror
C.
Convex mirror
D.
None of these
Ans:
Concave mirror
Explanation :
To see the inner part of ear and other parts, E.N.T doctors use a concave mirror. When the rays of light falls on reflecting surface of concave mirror, that time Concave mirror concentrate those all the rays at its focus.
[23] Fibre optics work on the principle of -
A.
scattering of light
B.
total internal absorption
C.
total internal reflection
D.
option rotation
Ans:
total internal reflection
Explanation :
An optical fibre is a cylindrical dielectric waveguide (non-conducting waveguide) that transmits light along its axis, by the process of total internal reflection.
[24] The reverse effect of X-ray emission is –
A.
Raman effect
B.
Compton effect
C.
Zeeman effect
D.
Photoelectric
Ans:
Photoelectric
Explanation :
When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
[25] The group of solar cells joined together in a definite pattern is called a –
A.
Battery
B.
Solar heater
C.
Solar cooker
D.
Solar cell panel
Ans:
Solar cell panel
Explanation :
A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a `solar cell panel'. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.
Explanation :
The equation v = u + at is called Newton's first equation of motion, where, u = Initial velocity, v = Final velocity, a = acceleration and t = time.
[10] What is the minimum distance (in metres) required to hear an echo?
A.
10
B.
13
C.
17
D.
21
Ans:
17
Explanation :
The human ear cannot distinguish echo from the original direct sound if the delay is less than 1/15 of a second. The velocity of sound in dry air is approximately 343 m/s at a temperature of 25⁰C.
[11] The intensity ratio of waves is 25:9. What is the ratio of their amplitudes?
A.
50 : 18
B.
25 : 9
C.
3 : 5
D.
5 : 3
Ans:
5 : 3
Explanation :
In general, the intensity of a wave is proportional to the square of its amplitude. This has an important implication: relative intensity can be obtained by squaring relative amplitude. So if the intensity ratio is 25:9, the amplitude ratio will be 5:3.
[12] Which of these travels in glass with minimum velocity?
A.
red light
B.
violet light
C.
green light
D.
yellow light
Ans:
violet light
Explanation :
Red light has a longer wavelength than violet light and the other colours of visible light have intermediate wavelengths. As light passes from air into glass, there is reduction of velocity. Due to longer wave-lengths, red waves travel fastest and is refracted the least, while violet waves travel the slowest and is refracted the most.
[13] The phenomenon which causes mirage is –
A.
Interference
B.
Diffraction
C.
Polarisation
D.
Total internal reflection
Ans:
Total internal reflection
Explanation :
Mirage is caused by total internal reflection in deserts where due to heating of the earth, refractive index of air near the surface of earth becomes lesser than above it. A ray of light coming from a distant object gets refracted from a denser to a rarer medium.
[14] Which of the following is indicated by the colour of a star?
A.
weight
B.
distance
C.
temperature
D.
size
Ans:
temperature
Explanation :
Colour is caused by the temperature of the surface of the star. A star approximates the behavior of a black body radiator. As a black body gets hotter its color changes. Small stars are cool (less than 3000°C) with a reddish appearance, whereas big heavy stars are hot (over 30,000°C), and have a bluish glow.
[15] For which one of the following, 'Diodes' are generally used for?
A.
Rectification
B.
Amplification
C.
Modulation
D.
Filtration
Ans:
Rectification
Explanation :
In electronics, a diode is an electronic device that allows current to flow in one direction only. It is mainly used as a rectifier diode that lets electrical current flow in only one direction and is mainly used for power supply operation. Rectifier diodes are used for changing alternating current into direct current.
[16] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in –
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[17] Which one among the following components is used as an amplifying device?
A.
Transformer
B.
Diode
C.
Capacitor
D.
Transistor
Ans:
Transistor
Explanation :
An amplifier is an electronic device that increases the voltage, current, or power of a signal. Generally transistors are active devices that can be used with discrete components to amplify voltage, power or both depending upon the configuration.
[18] The commonly used coolant in refrigerators is –
A.
Ammonia
B.
Nitrogen
C.
Freon
D.
Oxygen
Ans:
Freon
Explanation :
Modem refrigerators usually use a refrigerant called FIFC-134a (1,1,1,2-Tetrafluoroethane), which does not deplete the ozone layer, instead of Freon. Freon used to be the most common refrigerant till the 1980s; however, its use has declined since
[19] The term ‘Higgs Boson’ is associated with -
A.
Nano Technology
B.
Oncology
C.
God Particle
D.
Stem Cell Research
Ans:
God Particle
Explanation :
The Higgs boson is an elementary particle in the Standard Model of particle physics. That is often referred to as the “God particle” in popular media outside the scientific community.
[20] Kilowatt-hour (KWH) is the unit of -
A.
power
B.
resistance
C.
resistivity
D.
energy
Ans:
energy
Explanation :
The kilowatt hour (symbol kWh, kW⋅h or kW h) is a unit of energy equal to 3.6 mega joules. If the energy is being transmitted or used at a constant rate (power) over a period of time, the total energy in kilowatt hours is the power in kilowatts multiplied by the time in hours.
[21] Major portion of the earth’s crust is mainly constituted by -
A.
Oxygen and Iron
B.
Oxygen and Silicon
C.
Silicon and Iron
D.
Silicon and Aluminium
Ans:
Oxygen and Silicon
Explanation :
Oxygen is the most abundant element in the earth’s crust, comprising 46.6% or the crust by weight. Silicon 28%, aluminum 8.2%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium, 2.0%, and titanium 0.61% also comprise the crust.
[22] The mirror used by ENT specialist is:
A.
Plane mirror
B.
Concave mirror
C.
Convex mirror
D.
None of these
Ans:
Concave mirror
Explanation :
To see the inner part of ear and other parts, E.N.T doctors use a concave mirror. When the rays of light falls on reflecting surface of concave mirror, that time Concave mirror concentrate those all the rays at its focus.
[23] Fibre optics work on the principle of -
A.
scattering of light
B.
total internal absorption
C.
total internal reflection
D.
option rotation
Ans:
total internal reflection
Explanation :
An optical fibre is a cylindrical dielectric waveguide (non-conducting waveguide) that transmits light along its axis, by the process of total internal reflection.
[24] The reverse effect of X-ray emission is –
A.
Raman effect
B.
Compton effect
C.
Zeeman effect
D.
Photoelectric
Ans:
Photoelectric
Explanation :
When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
[25] The group of solar cells joined together in a definite pattern is called a –
A.
Battery
B.
Solar heater
C.
Solar cooker
D.
Solar cell panel
Ans:
Solar cell panel
Explanation :
A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a `solar cell panel'. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.
Explanation :
In general, the intensity of a wave is proportional to the square of its amplitude. This has an important implication: relative intensity can be obtained by squaring relative amplitude. So if the intensity ratio is 25:9, the amplitude ratio will be 5:3.
[12] Which of these travels in glass with minimum velocity?
A.
red light
B.
violet light
C.
green light
D.
yellow light
Ans:
violet light
Explanation :
Red light has a longer wavelength than violet light and the other colours of visible light have intermediate wavelengths. As light passes from air into glass, there is reduction of velocity. Due to longer wave-lengths, red waves travel fastest and is refracted the least, while violet waves travel the slowest and is refracted the most.
[13] The phenomenon which causes mirage is –
A.
Interference
B.
Diffraction
C.
Polarisation
D.
Total internal reflection
Ans:
Total internal reflection
Explanation :
Mirage is caused by total internal reflection in deserts where due to heating of the earth, refractive index of air near the surface of earth becomes lesser than above it. A ray of light coming from a distant object gets refracted from a denser to a rarer medium.
[14] Which of the following is indicated by the colour of a star?
A.
weight
B.
distance
C.
temperature
D.
size
Ans:
temperature
Explanation :
Colour is caused by the temperature of the surface of the star. A star approximates the behavior of a black body radiator. As a black body gets hotter its color changes. Small stars are cool (less than 3000°C) with a reddish appearance, whereas big heavy stars are hot (over 30,000°C), and have a bluish glow.
[15] For which one of the following, 'Diodes' are generally used for?
A.
Rectification
B.
Amplification
C.
Modulation
D.
Filtration
Ans:
Rectification
Explanation :
In electronics, a diode is an electronic device that allows current to flow in one direction only. It is mainly used as a rectifier diode that lets electrical current flow in only one direction and is mainly used for power supply operation. Rectifier diodes are used for changing alternating current into direct current.
[16] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in –
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[17] Which one among the following components is used as an amplifying device?
A.
Transformer
B.
Diode
C.
Capacitor
D.
Transistor
Ans:
Transistor
Explanation :
An amplifier is an electronic device that increases the voltage, current, or power of a signal. Generally transistors are active devices that can be used with discrete components to amplify voltage, power or both depending upon the configuration.
[18] The commonly used coolant in refrigerators is –
A.
Ammonia
B.
Nitrogen
C.
Freon
D.
Oxygen
Ans:
Freon
Explanation :
Modem refrigerators usually use a refrigerant called FIFC-134a (1,1,1,2-Tetrafluoroethane), which does not deplete the ozone layer, instead of Freon. Freon used to be the most common refrigerant till the 1980s; however, its use has declined since
[19] The term ‘Higgs Boson’ is associated with -
A.
Nano Technology
B.
Oncology
C.
God Particle
D.
Stem Cell Research
Ans:
God Particle
Explanation :
The Higgs boson is an elementary particle in the Standard Model of particle physics. That is often referred to as the “God particle” in popular media outside the scientific community.
[20] Kilowatt-hour (KWH) is the unit of -
A.
power
B.
resistance
C.
resistivity
D.
energy
Ans:
energy
Explanation :
The kilowatt hour (symbol kWh, kW⋅h or kW h) is a unit of energy equal to 3.6 mega joules. If the energy is being transmitted or used at a constant rate (power) over a period of time, the total energy in kilowatt hours is the power in kilowatts multiplied by the time in hours.
[21] Major portion of the earth’s crust is mainly constituted by -
A.
Oxygen and Iron
B.
Oxygen and Silicon
C.
Silicon and Iron
D.
Silicon and Aluminium
Ans:
Oxygen and Silicon
Explanation :
Oxygen is the most abundant element in the earth’s crust, comprising 46.6% or the crust by weight. Silicon 28%, aluminum 8.2%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium, 2.0%, and titanium 0.61% also comprise the crust.
[22] The mirror used by ENT specialist is:
A.
Plane mirror
B.
Concave mirror
C.
Convex mirror
D.
None of these
Ans:
Concave mirror
Explanation :
To see the inner part of ear and other parts, E.N.T doctors use a concave mirror. When the rays of light falls on reflecting surface of concave mirror, that time Concave mirror concentrate those all the rays at its focus.
[23] Fibre optics work on the principle of -
A.
scattering of light
B.
total internal absorption
C.
total internal reflection
D.
option rotation
Ans:
total internal reflection
Explanation :
An optical fibre is a cylindrical dielectric waveguide (non-conducting waveguide) that transmits light along its axis, by the process of total internal reflection.
[24] The reverse effect of X-ray emission is –
A.
Raman effect
B.
Compton effect
C.
Zeeman effect
D.
Photoelectric
Ans:
Photoelectric
Explanation :
When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
[25] The group of solar cells joined together in a definite pattern is called a –
A.
Battery
B.
Solar heater
C.
Solar cooker
D.
Solar cell panel
Ans:
Solar cell panel
Explanation :
A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a `solar cell panel'. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.
Explanation :
Mirage is caused by total internal reflection in deserts where due to heating of the earth, refractive index of air near the surface of earth becomes lesser than above it. A ray of light coming from a distant object gets refracted from a denser to a rarer medium.
[14] Which of the following is indicated by the colour of a star?
A.
weight
B.
distance
C.
temperature
D.
size
Ans:
temperature
Explanation :
Colour is caused by the temperature of the surface of the star. A star approximates the behavior of a black body radiator. As a black body gets hotter its color changes. Small stars are cool (less than 3000°C) with a reddish appearance, whereas big heavy stars are hot (over 30,000°C), and have a bluish glow.
[15] For which one of the following, 'Diodes' are generally used for?
A.
Rectification
B.
Amplification
C.
Modulation
D.
Filtration
Ans:
Rectification
Explanation :
In electronics, a diode is an electronic device that allows current to flow in one direction only. It is mainly used as a rectifier diode that lets electrical current flow in only one direction and is mainly used for power supply operation. Rectifier diodes are used for changing alternating current into direct current.
[16] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in –
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[17] Which one among the following components is used as an amplifying device?
A.
Transformer
B.
Diode
C.
Capacitor
D.
Transistor
Ans:
Transistor
Explanation :
An amplifier is an electronic device that increases the voltage, current, or power of a signal. Generally transistors are active devices that can be used with discrete components to amplify voltage, power or both depending upon the configuration.
[18] The commonly used coolant in refrigerators is –
A.
Ammonia
B.
Nitrogen
C.
Freon
D.
Oxygen
Ans:
Freon
Explanation :
Modem refrigerators usually use a refrigerant called FIFC-134a (1,1,1,2-Tetrafluoroethane), which does not deplete the ozone layer, instead of Freon. Freon used to be the most common refrigerant till the 1980s; however, its use has declined since
[19] The term ‘Higgs Boson’ is associated with -
A.
Nano Technology
B.
Oncology
C.
God Particle
D.
Stem Cell Research
Ans:
God Particle
Explanation :
The Higgs boson is an elementary particle in the Standard Model of particle physics. That is often referred to as the “God particle” in popular media outside the scientific community.
[20] Kilowatt-hour (KWH) is the unit of -
A.
power
B.
resistance
C.
resistivity
D.
energy
Ans:
energy
Explanation :
The kilowatt hour (symbol kWh, kW⋅h or kW h) is a unit of energy equal to 3.6 mega joules. If the energy is being transmitted or used at a constant rate (power) over a period of time, the total energy in kilowatt hours is the power in kilowatts multiplied by the time in hours.
[21] Major portion of the earth’s crust is mainly constituted by -
A.
Oxygen and Iron
B.
Oxygen and Silicon
C.
Silicon and Iron
D.
Silicon and Aluminium
Ans:
Oxygen and Silicon
Explanation :
Oxygen is the most abundant element in the earth’s crust, comprising 46.6% or the crust by weight. Silicon 28%, aluminum 8.2%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium, 2.0%, and titanium 0.61% also comprise the crust.
[22] The mirror used by ENT specialist is:
A.
Plane mirror
B.
Concave mirror
C.
Convex mirror
D.
None of these
Ans:
Concave mirror
Explanation :
To see the inner part of ear and other parts, E.N.T doctors use a concave mirror. When the rays of light falls on reflecting surface of concave mirror, that time Concave mirror concentrate those all the rays at its focus.
[23] Fibre optics work on the principle of -
A.
scattering of light
B.
total internal absorption
C.
total internal reflection
D.
option rotation
Ans:
total internal reflection
Explanation :
An optical fibre is a cylindrical dielectric waveguide (non-conducting waveguide) that transmits light along its axis, by the process of total internal reflection.
[24] The reverse effect of X-ray emission is –
A.
Raman effect
B.
Compton effect
C.
Zeeman effect
D.
Photoelectric
Ans:
Photoelectric
Explanation :
When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
[25] The group of solar cells joined together in a definite pattern is called a –
A.
Battery
B.
Solar heater
C.
Solar cooker
D.
Solar cell panel
Ans:
Solar cell panel
Explanation :
A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a `solar cell panel'. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.
Explanation :
In electronics, a diode is an electronic device that allows current to flow in one direction only. It is mainly used as a rectifier diode that lets electrical current flow in only one direction and is mainly used for power supply operation. Rectifier diodes are used for changing alternating current into direct current.
[16] Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in –
A.
Conduction
B.
Convection
C.
Radiation
D.
Both conduction and convection
Ans:
Convection
Explanation :
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
[17] Which one among the following components is used as an amplifying device?
A.
Transformer
B.
Diode
C.
Capacitor
D.
Transistor
Ans:
Transistor
Explanation :
An amplifier is an electronic device that increases the voltage, current, or power of a signal. Generally transistors are active devices that can be used with discrete components to amplify voltage, power or both depending upon the configuration.
[18] The commonly used coolant in refrigerators is –
A.
Ammonia
B.
Nitrogen
C.
Freon
D.
Oxygen
Ans:
Freon
Explanation :
Modem refrigerators usually use a refrigerant called FIFC-134a (1,1,1,2-Tetrafluoroethane), which does not deplete the ozone layer, instead of Freon. Freon used to be the most common refrigerant till the 1980s; however, its use has declined since
[19] The term ‘Higgs Boson’ is associated with -
A.
Nano Technology
B.
Oncology
C.
God Particle
D.
Stem Cell Research
Ans:
God Particle
Explanation :
The Higgs boson is an elementary particle in the Standard Model of particle physics. That is often referred to as the “God particle” in popular media outside the scientific community.
[20] Kilowatt-hour (KWH) is the unit of -
A.
power
B.
resistance
C.
resistivity
D.
energy
Ans:
energy
Explanation :
The kilowatt hour (symbol kWh, kW⋅h or kW h) is a unit of energy equal to 3.6 mega joules. If the energy is being transmitted or used at a constant rate (power) over a period of time, the total energy in kilowatt hours is the power in kilowatts multiplied by the time in hours.
[21] Major portion of the earth’s crust is mainly constituted by -
A.
Oxygen and Iron
B.
Oxygen and Silicon
C.
Silicon and Iron
D.
Silicon and Aluminium
Ans:
Oxygen and Silicon
Explanation :
Oxygen is the most abundant element in the earth’s crust, comprising 46.6% or the crust by weight. Silicon 28%, aluminum 8.2%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium, 2.0%, and titanium 0.61% also comprise the crust.
[22] The mirror used by ENT specialist is:
A.
Plane mirror
B.
Concave mirror
C.
Convex mirror
D.
None of these
Ans:
Concave mirror
Explanation :
To see the inner part of ear and other parts, E.N.T doctors use a concave mirror. When the rays of light falls on reflecting surface of concave mirror, that time Concave mirror concentrate those all the rays at its focus.
[23] Fibre optics work on the principle of -
A.
scattering of light
B.
total internal absorption
C.
total internal reflection
D.
option rotation
Ans:
total internal reflection
Explanation :
An optical fibre is a cylindrical dielectric waveguide (non-conducting waveguide) that transmits light along its axis, by the process of total internal reflection.
[24] The reverse effect of X-ray emission is –
A.
Raman effect
B.
Compton effect
C.
Zeeman effect
D.
Photoelectric
Ans:
Photoelectric
Explanation :
When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
[25] The group of solar cells joined together in a definite pattern is called a –
A.
Battery
B.
Solar heater
C.
Solar cooker
D.
Solar cell panel
Ans:
Solar cell panel
Explanation :
A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a `solar cell panel'. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.
Explanation :
An amplifier is an electronic device that increases the voltage, current, or power of a signal. Generally transistors are active devices that can be used with discrete components to amplify voltage, power or both depending upon the configuration.
[18] The commonly used coolant in refrigerators is –
A.
Ammonia
B.
Nitrogen
C.
Freon
D.
Oxygen
Ans:
Freon
Explanation :
Modem refrigerators usually use a refrigerant called FIFC-134a (1,1,1,2-Tetrafluoroethane), which does not deplete the ozone layer, instead of Freon. Freon used to be the most common refrigerant till the 1980s; however, its use has declined since
[19] The term ‘Higgs Boson’ is associated with -
A.
Nano Technology
B.
Oncology
C.
God Particle
D.
Stem Cell Research
Ans:
God Particle
Explanation :
The Higgs boson is an elementary particle in the Standard Model of particle physics. That is often referred to as the “God particle” in popular media outside the scientific community.
[20] Kilowatt-hour (KWH) is the unit of -
A.
power
B.
resistance
C.
resistivity
D.
energy
Ans:
energy
Explanation :
The kilowatt hour (symbol kWh, kW⋅h or kW h) is a unit of energy equal to 3.6 mega joules. If the energy is being transmitted or used at a constant rate (power) over a period of time, the total energy in kilowatt hours is the power in kilowatts multiplied by the time in hours.
[21] Major portion of the earth’s crust is mainly constituted by -
A.
Oxygen and Iron
B.
Oxygen and Silicon
C.
Silicon and Iron
D.
Silicon and Aluminium
Ans:
Oxygen and Silicon
Explanation :
Oxygen is the most abundant element in the earth’s crust, comprising 46.6% or the crust by weight. Silicon 28%, aluminum 8.2%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium, 2.0%, and titanium 0.61% also comprise the crust.
[22] The mirror used by ENT specialist is:
A.
Plane mirror
B.
Concave mirror
C.
Convex mirror
D.
None of these
Ans:
Concave mirror
Explanation :
To see the inner part of ear and other parts, E.N.T doctors use a concave mirror. When the rays of light falls on reflecting surface of concave mirror, that time Concave mirror concentrate those all the rays at its focus.
[23] Fibre optics work on the principle of -
A.
scattering of light
B.
total internal absorption
C.
total internal reflection
D.
option rotation
Ans:
total internal reflection
Explanation :
An optical fibre is a cylindrical dielectric waveguide (non-conducting waveguide) that transmits light along its axis, by the process of total internal reflection.
[24] The reverse effect of X-ray emission is –
A.
Raman effect
B.
Compton effect
C.
Zeeman effect
D.
Photoelectric
Ans:
Photoelectric
Explanation :
When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
[25] The group of solar cells joined together in a definite pattern is called a –
A.
Battery
B.
Solar heater
C.
Solar cooker
D.
Solar cell panel
Ans:
Solar cell panel
Explanation :
A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a `solar cell panel'. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.
Explanation :
The Higgs boson is an elementary particle in the Standard Model of particle physics. That is often referred to as the “God particle” in popular media outside the scientific community.
[20] Kilowatt-hour (KWH) is the unit of -
A.
power
B.
resistance
C.
resistivity
D.
energy
Ans:
energy
Explanation :
The kilowatt hour (symbol kWh, kW⋅h or kW h) is a unit of energy equal to 3.6 mega joules. If the energy is being transmitted or used at a constant rate (power) over a period of time, the total energy in kilowatt hours is the power in kilowatts multiplied by the time in hours.
[21] Major portion of the earth’s crust is mainly constituted by -
A.
Oxygen and Iron
B.
Oxygen and Silicon
C.
Silicon and Iron
D.
Silicon and Aluminium
Ans:
Oxygen and Silicon
Explanation :
Oxygen is the most abundant element in the earth’s crust, comprising 46.6% or the crust by weight. Silicon 28%, aluminum 8.2%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium, 2.0%, and titanium 0.61% also comprise the crust.
[22] The mirror used by ENT specialist is:
A.
Plane mirror
B.
Concave mirror
C.
Convex mirror
D.
None of these
Ans:
Concave mirror
Explanation :
To see the inner part of ear and other parts, E.N.T doctors use a concave mirror. When the rays of light falls on reflecting surface of concave mirror, that time Concave mirror concentrate those all the rays at its focus.
[23] Fibre optics work on the principle of -
A.
scattering of light
B.
total internal absorption
C.
total internal reflection
D.
option rotation
Ans:
total internal reflection
Explanation :
An optical fibre is a cylindrical dielectric waveguide (non-conducting waveguide) that transmits light along its axis, by the process of total internal reflection.
[24] The reverse effect of X-ray emission is –
A.
Raman effect
B.
Compton effect
C.
Zeeman effect
D.
Photoelectric
Ans:
Photoelectric
Explanation :
When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
[25] The group of solar cells joined together in a definite pattern is called a –
A.
Battery
B.
Solar heater
C.
Solar cooker
D.
Solar cell panel
Ans:
Solar cell panel
Explanation :
A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a `solar cell panel'. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.
Explanation :
Oxygen is the most abundant element in the earth’s crust, comprising 46.6% or the crust by weight. Silicon 28%, aluminum 8.2%, iron 5.6%, calcium 4.2%, sodium 2.5%, magnesium 2.4%, potassium, 2.0%, and titanium 0.61% also comprise the crust.
[22] The mirror used by ENT specialist is:
A.
Plane mirror
B.
Concave mirror
C.
Convex mirror
D.
None of these
Ans:
Concave mirror
Explanation :
To see the inner part of ear and other parts, E.N.T doctors use a concave mirror. When the rays of light falls on reflecting surface of concave mirror, that time Concave mirror concentrate those all the rays at its focus.
[23] Fibre optics work on the principle of -
A.
scattering of light
B.
total internal absorption
C.
total internal reflection
D.
option rotation
Ans:
total internal reflection
Explanation :
An optical fibre is a cylindrical dielectric waveguide (non-conducting waveguide) that transmits light along its axis, by the process of total internal reflection.
[24] The reverse effect of X-ray emission is –
A.
Raman effect
B.
Compton effect
C.
Zeeman effect
D.
Photoelectric
Ans:
Photoelectric
Explanation :
When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
[25] The group of solar cells joined together in a definite pattern is called a –
A.
Battery
B.
Solar heater
C.
Solar cooker
D.
Solar cell panel
Ans:
Solar cell panel
Explanation :
A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a `solar cell panel'. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.
Explanation :
An optical fibre is a cylindrical dielectric waveguide (non-conducting waveguide) that transmits light along its axis, by the process of total internal reflection.
[24] The reverse effect of X-ray emission is –
A.
Raman effect
B.
Compton effect
C.
Zeeman effect
D.
Photoelectric
Ans:
Photoelectric
Explanation :
When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
[25] The group of solar cells joined together in a definite pattern is called a –
A.
Battery
B.
Solar heater
C.
Solar cooker
D.
Solar cell panel
Ans:
Solar cell panel
Explanation :
A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a `solar cell panel'. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.
Explanation :
A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a `solar cell panel'. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.