[1] The phenomenon of radioactivity was discovered by -
A.
Marie Curie
B.
Pierre Curie
C.
Henri Becquerel
D.
J.J. Thomson
Ans:
Henri Becquerel
Explanation :
French physicist Henri Becquerel discovered radioactivity by accident in 1896 when a piece of uranium left in a dark desk drawer made an image on photographic plates. The husband and wife team of Pierre and Marie Curie became interested in Becquerel’s discovery. While experimenting with their own uranium-containing ore, they came up with the term “radioactivity” to describe the spontaneous emissions that they studied.
[2] If the velocity-time graph of a particle is represented by y = mt + c, then the particle is moving with–
A.
constant speed
B.
constant velocity
C.
constant acceleration
D.
varying acceleration
Ans:
constant acceleration
Explanation :
In this case the given equation shows that that the velocity is linear with time and therefore the particle is moving with constant acceleration because for a particle to acquire constant acceleration the graph of the velocity time graph should be in linear with the time function.
[3] In a photocell light energy is converted into –
A.
Potential energy
B.
Chemical energy
C.
Heat energy
D.
Electrical energy
Ans:
Electrical energy
Explanation :
Photocells are scientifically known as photo-resistors. A photo-resistor or light dependent resistor (LDR) is a resistor whose resistance decreases with increasing incident light intensity; in other words, it exhibits photoconductivity. A photo-resistor is made of a high resistance semiconductor. If light falling on the device is of high enough frequency, photons absorbed by the semiconductor give bound electrons enough energy to jump into the conduction band. The resulting free electron conduct electricity, thereby lowering resistance. Photo-resistors are basically photocells.
[4] A storm is predicted if atmospheric pressure –
A.
Rises suddenly
B.
Rises gradually
C.
Falls suddenly
D.
Falls gradually
Ans:
Falls suddenly
Explanation :
Atmospheric pressure is basically the weight of air in the atmosphere above the reservoir, so the level of mercury continues to change until the weight of mercury in the glass tube is exactly equal to the weight of air above the reservoir. In areas of low pressure, air is rising away from the surface of the earth more quickly than it can be replaced by air flowing in from surrounding areas. This reduces the weight of air above the reservoir so the mercury level drops to a lower level.
[5] The smallest unit of classification is -
A.
Species
B.
Genus
C.
Family
D.
Order
Ans:
Species
Explanation :
Species is the basic unit for understanding taxonomy, that occupies a key position. It is defined as a dynamic genetically distinct group of organisms, which resemble each other in all respect and freely interbreed among themselves to produce fertile offsprings.
[6] Light from the Sun reaches us in nearly -
A.
2 minutes
B.
4 minutes
C.
8 minutes
D.
16 minutes
Ans:
8 minutes
Explanation :
The sun's light takes about 8 minutes to reach the Earth after it has been emitted from the sun's surface. The time it takes for light to reach planets in our Solar System (not the Milky Way, which is our galaxy) varies from about 3 minutes for Mercury, to about 5.3 hours for Pluto
[7] A concave lens always forms an image which is –
A.
Real and erect
B.
Virtual and erect
C.
Real and inverted
D.
Virtual and inverted
Ans:
Virtual and erect
Explanation :
Concave lens possesses at least one surface that curves inwards. It is a diverging lens, spreading out those light rays that have been refracted through it. A concave lens is thinner at its centre than at its edges, and is used to correct short-sightedness (myopia). After light rays have passed through the lens, they appear to come from a point called the principal focus. The image formed by a concave lens is virtual, upright, and smaller than the object, and it cannot be projected onto a screen.
[8] One can distinguish a telescope from a microscope by observing –
A.
length
B.
colour
C.
size of the lens
D.
length and size of the lens
Ans:
length and size of the lens
Explanation :
Telescope and Microscope are two scientific instruments that serve their purposes differently. One of the main differences between a telescope and a microscope is that a telescope is used to view things that are far whereas a microscope is used to view things that are very near. Another important difference between telescope and microscope is that the focal length or the distance from the focal point to the lens is different in these two scientific instruments.
[9] The sound produced by a bat is –
A.
audible
B.
subsonic
C.
infrasonic
D.
ultrasonic
Ans:
ultrasonic
Explanation :
Although bats use echolocation to detect their prey, and find their way around in the dark, the sounds which they emit are 'ultrasonic', which is another way of saying they are beyond the range of normal human hearing. Ultrasound is a cyclic sound pressure wave with a frequency greater than the upper limit of the human hearing range. Ultrasound is thus not separated from "normal" (audible) sound based on differences in physical properties, only the fact that humans cannot hear it.
[10] The image of an object formed on the retina of the eye is -
A.
virtual and upright
B.
virtual and inverted
C.
real and inverted
D.
Real and upright
Ans:
real and inverted
Explanation :
The retina is the thin light-sensitive membrane lining the inner eyeball towards the back of the eye. When the light goes into the eye it must pass through the lens (a biconvex lens), which inverts the image we are seeing. When we look at an image, light bounces it into our eye. As it enters our eye and passes through the lens the image gets inverted- reversed and flipped the other way- so that the image on our retina looks like an upside down object going from right to left instead of left to right. Once this image is set on the retina, cone cells distinguish the colour and detail, while rod cells distinguish movement and shades of grey.
[11] In a nuclear reactor, one of the following is used as a fuel.
A.
Coal
B.
Uranium
C.
Radium
D.
Diesel
Ans:
Uranium
Explanation :
Many contemporary uses of uranium exploit its unique nuclear properties. Uranium-235 has the distinction of being the only naturally occurring fissile isotope. Uranium-238 is fissionable by fast neutrons, and is fertile, meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor. Another fissile isotope, uranium-233, can be produced from natural thorium and is also important in nuclear technology.
[12] Suns heat reaches us by –
A.
Conduction
B.
Convection
C.
Radiation
D.
Reflection
Ans:
Radiation
Explanation :
Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. The sun's rays reach us in the form of electromagnetic radiation. This type of radiation covers a wide spectrum (that is a wide range of frequencies), but those from the sun are mainly infra-red, visible, and ultraviolet.
[13] A colour-blind person cannot –
A.
See distant objects
B.
See black colour
C.
Distinguish between certain colours
D.
Have persistence of vision
Ans:
Distinguish between certain colours
Explanation :
Colour blindness or colour vision deficiency is the inability or decreased ability to see coluor, or perceive colour differences, under normal lighting conditions. The most usual cause is a fault in the development of one or more sets of retinal cones that perceive colour in light and transmit that information to the optic nerve. This type of colour blindness is usually a sex-linked condition.
[14] Forged documents are detected by –
A.
ultraviolet rays
B.
infra-red rays
C.
beta rays
D.
gamma rays
Ans:
ultraviolet rays
Explanation :
Old postcards, books, signs, photos and other paper products made before the late 1930s rarely glow under a black light. Chemical bleaches and dyes used in modern papers will fluoresce under ultraviolet light. Knowing this helps to detect forged documents and distinguish reproductions in all types of ephemera.
[15] In which medium, velocity of sound is maximum?
A.
Metals
B.
Air
C.
Water
D.
Polymer
Ans:
Metals
Explanation :
The speed of sound is highest in solid. The speed of sound depends on the density of the medium through which it is travelling.
[16] If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same -
A.
velocity
B.
momentum
C.
acceleration
D.
kinetic energy
Ans:
momentum
Explanation :
If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same momentum.
[17] The compound of a metal found in nature is called -
A.
Mineral
B.
Ore
C.
Flux
D.
Slag
Ans:
Mineral
Explanation :
Metals are an integral part of our planet and are found in almost all rocks and soils. Most metals form compounds called minerals, which are naturally occurring, inorganic solids with regular chemical compositions and crystal structures.
[18] Decibel is used to measure the intensity of -
A.
Magnetic field
B.
Sound
C.
Light
D.
Heat
Ans:
Sound
Explanation :
The decibel (abbreviated dB) is the unit used to measure the intensity of a sound. The decibel scale is a little odd because the human ear is incredibly sensitive. Our ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine. The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. The decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory.
[19] Rainbow is seen after rain because of hanging molecules of water which act as –
A.
lenses
B.
mirrors
C.
(2) prisms
D.
slabs
Ans:
mirrors
Explanation :
In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. In a rainbow, raindrops in the air act as tiny prisms. Light enters the raindrop, reflects off of the side of the drop and exits. In the process, it is broken into a spectrum just like it is in a triangular glass prism.
[20] Which of the following is a result of Surface tension?
A.
Gravitational pull
B.
Viscosity
C.
Capillary action
D.
Radiation
Ans:
Capillary action
Explanation :
Capillary action is the result of adhesion and surface tension. Adhesion of water to the walls of a vessel will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. The surface tension acts to hold the surface intact, so instead of just the edges moving upward, the whole liquid surface is dragged upward.
[21] Water is used in car radiator because of its –
A.
low density
B.
easy availability
C.
high specific heat capacity
D.
low boiling point
Ans:
high specific heat capacity
Explanation :
Water is used in car radiators because the Specific heat capacity of water is high as a result of which it takes away the heat from engine better compared to other liquids. This is a form of coolant used in the radiator. If the radiator was to overheat the car would come to a stop.
[22] If a metal can be drawn into wires relatively easily it is called:
A.
malleable
B.
ductile
C.
extractive
D.
tactile
Ans:
ductile
Explanation :
Ductility is a physical property of a material associated with the ability to be hammered thin or stretched into wire without breaking.
[23] At what temperature a body will not radiate any heat energy?
A.
0° C
B.
273° C
C.
100° C
D.
-273° C
Ans:
-273° C
Explanation :
All physical bodies with temperature over absolute zero (0 K or − 273°C) radiate energy in the form of electromagnetic waves.
[24] The mirror used for the head light of a car is –
A.
spherical concave
B.
plane
C.
cylindrical
D.
parabolic concave
Ans:
parabolic concave
Explanation :
Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.
[25] Knot is a measure of -
A.
Unit of speed
B.
the curvature of spherical objects
C.
solar radiation
D.
intensiry of earthquake shock
Ans:
Unit of speed
Explanation :
The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.
Explanation :
French physicist Henri Becquerel discovered radioactivity by accident in 1896 when a piece of uranium left in a dark desk drawer made an image on photographic plates. The husband and wife team of Pierre and Marie Curie became interested in Becquerel’s discovery. While experimenting with their own uranium-containing ore, they came up with the term “radioactivity” to describe the spontaneous emissions that they studied.
[2] If the velocity-time graph of a particle is represented by y = mt + c, then the particle is moving with–
A.
constant speed
B.
constant velocity
C.
constant acceleration
D.
varying acceleration
Ans:
constant acceleration
Explanation :
In this case the given equation shows that that the velocity is linear with time and therefore the particle is moving with constant acceleration because for a particle to acquire constant acceleration the graph of the velocity time graph should be in linear with the time function.
[3] In a photocell light energy is converted into –
A.
Potential energy
B.
Chemical energy
C.
Heat energy
D.
Electrical energy
Ans:
Electrical energy
Explanation :
Photocells are scientifically known as photo-resistors. A photo-resistor or light dependent resistor (LDR) is a resistor whose resistance decreases with increasing incident light intensity; in other words, it exhibits photoconductivity. A photo-resistor is made of a high resistance semiconductor. If light falling on the device is of high enough frequency, photons absorbed by the semiconductor give bound electrons enough energy to jump into the conduction band. The resulting free electron conduct electricity, thereby lowering resistance. Photo-resistors are basically photocells.
[4] A storm is predicted if atmospheric pressure –
A.
Rises suddenly
B.
Rises gradually
C.
Falls suddenly
D.
Falls gradually
Ans:
Falls suddenly
Explanation :
Atmospheric pressure is basically the weight of air in the atmosphere above the reservoir, so the level of mercury continues to change until the weight of mercury in the glass tube is exactly equal to the weight of air above the reservoir. In areas of low pressure, air is rising away from the surface of the earth more quickly than it can be replaced by air flowing in from surrounding areas. This reduces the weight of air above the reservoir so the mercury level drops to a lower level.
[5] The smallest unit of classification is -
A.
Species
B.
Genus
C.
Family
D.
Order
Ans:
Species
Explanation :
Species is the basic unit for understanding taxonomy, that occupies a key position. It is defined as a dynamic genetically distinct group of organisms, which resemble each other in all respect and freely interbreed among themselves to produce fertile offsprings.
[6] Light from the Sun reaches us in nearly -
A.
2 minutes
B.
4 minutes
C.
8 minutes
D.
16 minutes
Ans:
8 minutes
Explanation :
The sun's light takes about 8 minutes to reach the Earth after it has been emitted from the sun's surface. The time it takes for light to reach planets in our Solar System (not the Milky Way, which is our galaxy) varies from about 3 minutes for Mercury, to about 5.3 hours for Pluto
[7] A concave lens always forms an image which is –
A.
Real and erect
B.
Virtual and erect
C.
Real and inverted
D.
Virtual and inverted
Ans:
Virtual and erect
Explanation :
Concave lens possesses at least one surface that curves inwards. It is a diverging lens, spreading out those light rays that have been refracted through it. A concave lens is thinner at its centre than at its edges, and is used to correct short-sightedness (myopia). After light rays have passed through the lens, they appear to come from a point called the principal focus. The image formed by a concave lens is virtual, upright, and smaller than the object, and it cannot be projected onto a screen.
[8] One can distinguish a telescope from a microscope by observing –
A.
length
B.
colour
C.
size of the lens
D.
length and size of the lens
Ans:
length and size of the lens
Explanation :
Telescope and Microscope are two scientific instruments that serve their purposes differently. One of the main differences between a telescope and a microscope is that a telescope is used to view things that are far whereas a microscope is used to view things that are very near. Another important difference between telescope and microscope is that the focal length or the distance from the focal point to the lens is different in these two scientific instruments.
[9] The sound produced by a bat is –
A.
audible
B.
subsonic
C.
infrasonic
D.
ultrasonic
Ans:
ultrasonic
Explanation :
Although bats use echolocation to detect their prey, and find their way around in the dark, the sounds which they emit are 'ultrasonic', which is another way of saying they are beyond the range of normal human hearing. Ultrasound is a cyclic sound pressure wave with a frequency greater than the upper limit of the human hearing range. Ultrasound is thus not separated from "normal" (audible) sound based on differences in physical properties, only the fact that humans cannot hear it.
[10] The image of an object formed on the retina of the eye is -
A.
virtual and upright
B.
virtual and inverted
C.
real and inverted
D.
Real and upright
Ans:
real and inverted
Explanation :
The retina is the thin light-sensitive membrane lining the inner eyeball towards the back of the eye. When the light goes into the eye it must pass through the lens (a biconvex lens), which inverts the image we are seeing. When we look at an image, light bounces it into our eye. As it enters our eye and passes through the lens the image gets inverted- reversed and flipped the other way- so that the image on our retina looks like an upside down object going from right to left instead of left to right. Once this image is set on the retina, cone cells distinguish the colour and detail, while rod cells distinguish movement and shades of grey.
[11] In a nuclear reactor, one of the following is used as a fuel.
A.
Coal
B.
Uranium
C.
Radium
D.
Diesel
Ans:
Uranium
Explanation :
Many contemporary uses of uranium exploit its unique nuclear properties. Uranium-235 has the distinction of being the only naturally occurring fissile isotope. Uranium-238 is fissionable by fast neutrons, and is fertile, meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor. Another fissile isotope, uranium-233, can be produced from natural thorium and is also important in nuclear technology.
[12] Suns heat reaches us by –
A.
Conduction
B.
Convection
C.
Radiation
D.
Reflection
Ans:
Radiation
Explanation :
Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. The sun's rays reach us in the form of electromagnetic radiation. This type of radiation covers a wide spectrum (that is a wide range of frequencies), but those from the sun are mainly infra-red, visible, and ultraviolet.
[13] A colour-blind person cannot –
A.
See distant objects
B.
See black colour
C.
Distinguish between certain colours
D.
Have persistence of vision
Ans:
Distinguish between certain colours
Explanation :
Colour blindness or colour vision deficiency is the inability or decreased ability to see coluor, or perceive colour differences, under normal lighting conditions. The most usual cause is a fault in the development of one or more sets of retinal cones that perceive colour in light and transmit that information to the optic nerve. This type of colour blindness is usually a sex-linked condition.
[14] Forged documents are detected by –
A.
ultraviolet rays
B.
infra-red rays
C.
beta rays
D.
gamma rays
Ans:
ultraviolet rays
Explanation :
Old postcards, books, signs, photos and other paper products made before the late 1930s rarely glow under a black light. Chemical bleaches and dyes used in modern papers will fluoresce under ultraviolet light. Knowing this helps to detect forged documents and distinguish reproductions in all types of ephemera.
[15] In which medium, velocity of sound is maximum?
A.
Metals
B.
Air
C.
Water
D.
Polymer
Ans:
Metals
Explanation :
The speed of sound is highest in solid. The speed of sound depends on the density of the medium through which it is travelling.
[16] If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same -
A.
velocity
B.
momentum
C.
acceleration
D.
kinetic energy
Ans:
momentum
Explanation :
If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same momentum.
[17] The compound of a metal found in nature is called -
A.
Mineral
B.
Ore
C.
Flux
D.
Slag
Ans:
Mineral
Explanation :
Metals are an integral part of our planet and are found in almost all rocks and soils. Most metals form compounds called minerals, which are naturally occurring, inorganic solids with regular chemical compositions and crystal structures.
[18] Decibel is used to measure the intensity of -
A.
Magnetic field
B.
Sound
C.
Light
D.
Heat
Ans:
Sound
Explanation :
The decibel (abbreviated dB) is the unit used to measure the intensity of a sound. The decibel scale is a little odd because the human ear is incredibly sensitive. Our ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine. The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. The decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory.
[19] Rainbow is seen after rain because of hanging molecules of water which act as –
A.
lenses
B.
mirrors
C.
(2) prisms
D.
slabs
Ans:
mirrors
Explanation :
In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. In a rainbow, raindrops in the air act as tiny prisms. Light enters the raindrop, reflects off of the side of the drop and exits. In the process, it is broken into a spectrum just like it is in a triangular glass prism.
[20] Which of the following is a result of Surface tension?
A.
Gravitational pull
B.
Viscosity
C.
Capillary action
D.
Radiation
Ans:
Capillary action
Explanation :
Capillary action is the result of adhesion and surface tension. Adhesion of water to the walls of a vessel will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. The surface tension acts to hold the surface intact, so instead of just the edges moving upward, the whole liquid surface is dragged upward.
[21] Water is used in car radiator because of its –
A.
low density
B.
easy availability
C.
high specific heat capacity
D.
low boiling point
Ans:
high specific heat capacity
Explanation :
Water is used in car radiators because the Specific heat capacity of water is high as a result of which it takes away the heat from engine better compared to other liquids. This is a form of coolant used in the radiator. If the radiator was to overheat the car would come to a stop.
[22] If a metal can be drawn into wires relatively easily it is called:
A.
malleable
B.
ductile
C.
extractive
D.
tactile
Ans:
ductile
Explanation :
Ductility is a physical property of a material associated with the ability to be hammered thin or stretched into wire without breaking.
[23] At what temperature a body will not radiate any heat energy?
A.
0° C
B.
273° C
C.
100° C
D.
-273° C
Ans:
-273° C
Explanation :
All physical bodies with temperature over absolute zero (0 K or − 273°C) radiate energy in the form of electromagnetic waves.
[24] The mirror used for the head light of a car is –
A.
spherical concave
B.
plane
C.
cylindrical
D.
parabolic concave
Ans:
parabolic concave
Explanation :
Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.
[25] Knot is a measure of -
A.
Unit of speed
B.
the curvature of spherical objects
C.
solar radiation
D.
intensiry of earthquake shock
Ans:
Unit of speed
Explanation :
The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.
Explanation :
Photocells are scientifically known as photo-resistors. A photo-resistor or light dependent resistor (LDR) is a resistor whose resistance decreases with increasing incident light intensity; in other words, it exhibits photoconductivity. A photo-resistor is made of a high resistance semiconductor. If light falling on the device is of high enough frequency, photons absorbed by the semiconductor give bound electrons enough energy to jump into the conduction band. The resulting free electron conduct electricity, thereby lowering resistance. Photo-resistors are basically photocells.
[4] A storm is predicted if atmospheric pressure –
A.
Rises suddenly
B.
Rises gradually
C.
Falls suddenly
D.
Falls gradually
Ans:
Falls suddenly
Explanation :
Atmospheric pressure is basically the weight of air in the atmosphere above the reservoir, so the level of mercury continues to change until the weight of mercury in the glass tube is exactly equal to the weight of air above the reservoir. In areas of low pressure, air is rising away from the surface of the earth more quickly than it can be replaced by air flowing in from surrounding areas. This reduces the weight of air above the reservoir so the mercury level drops to a lower level.
[5] The smallest unit of classification is -
A.
Species
B.
Genus
C.
Family
D.
Order
Ans:
Species
Explanation :
Species is the basic unit for understanding taxonomy, that occupies a key position. It is defined as a dynamic genetically distinct group of organisms, which resemble each other in all respect and freely interbreed among themselves to produce fertile offsprings.
[6] Light from the Sun reaches us in nearly -
A.
2 minutes
B.
4 minutes
C.
8 minutes
D.
16 minutes
Ans:
8 minutes
Explanation :
The sun's light takes about 8 minutes to reach the Earth after it has been emitted from the sun's surface. The time it takes for light to reach planets in our Solar System (not the Milky Way, which is our galaxy) varies from about 3 minutes for Mercury, to about 5.3 hours for Pluto
[7] A concave lens always forms an image which is –
A.
Real and erect
B.
Virtual and erect
C.
Real and inverted
D.
Virtual and inverted
Ans:
Virtual and erect
Explanation :
Concave lens possesses at least one surface that curves inwards. It is a diverging lens, spreading out those light rays that have been refracted through it. A concave lens is thinner at its centre than at its edges, and is used to correct short-sightedness (myopia). After light rays have passed through the lens, they appear to come from a point called the principal focus. The image formed by a concave lens is virtual, upright, and smaller than the object, and it cannot be projected onto a screen.
[8] One can distinguish a telescope from a microscope by observing –
A.
length
B.
colour
C.
size of the lens
D.
length and size of the lens
Ans:
length and size of the lens
Explanation :
Telescope and Microscope are two scientific instruments that serve their purposes differently. One of the main differences between a telescope and a microscope is that a telescope is used to view things that are far whereas a microscope is used to view things that are very near. Another important difference between telescope and microscope is that the focal length or the distance from the focal point to the lens is different in these two scientific instruments.
[9] The sound produced by a bat is –
A.
audible
B.
subsonic
C.
infrasonic
D.
ultrasonic
Ans:
ultrasonic
Explanation :
Although bats use echolocation to detect their prey, and find their way around in the dark, the sounds which they emit are 'ultrasonic', which is another way of saying they are beyond the range of normal human hearing. Ultrasound is a cyclic sound pressure wave with a frequency greater than the upper limit of the human hearing range. Ultrasound is thus not separated from "normal" (audible) sound based on differences in physical properties, only the fact that humans cannot hear it.
[10] The image of an object formed on the retina of the eye is -
A.
virtual and upright
B.
virtual and inverted
C.
real and inverted
D.
Real and upright
Ans:
real and inverted
Explanation :
The retina is the thin light-sensitive membrane lining the inner eyeball towards the back of the eye. When the light goes into the eye it must pass through the lens (a biconvex lens), which inverts the image we are seeing. When we look at an image, light bounces it into our eye. As it enters our eye and passes through the lens the image gets inverted- reversed and flipped the other way- so that the image on our retina looks like an upside down object going from right to left instead of left to right. Once this image is set on the retina, cone cells distinguish the colour and detail, while rod cells distinguish movement and shades of grey.
[11] In a nuclear reactor, one of the following is used as a fuel.
A.
Coal
B.
Uranium
C.
Radium
D.
Diesel
Ans:
Uranium
Explanation :
Many contemporary uses of uranium exploit its unique nuclear properties. Uranium-235 has the distinction of being the only naturally occurring fissile isotope. Uranium-238 is fissionable by fast neutrons, and is fertile, meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor. Another fissile isotope, uranium-233, can be produced from natural thorium and is also important in nuclear technology.
[12] Suns heat reaches us by –
A.
Conduction
B.
Convection
C.
Radiation
D.
Reflection
Ans:
Radiation
Explanation :
Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. The sun's rays reach us in the form of electromagnetic radiation. This type of radiation covers a wide spectrum (that is a wide range of frequencies), but those from the sun are mainly infra-red, visible, and ultraviolet.
[13] A colour-blind person cannot –
A.
See distant objects
B.
See black colour
C.
Distinguish between certain colours
D.
Have persistence of vision
Ans:
Distinguish between certain colours
Explanation :
Colour blindness or colour vision deficiency is the inability or decreased ability to see coluor, or perceive colour differences, under normal lighting conditions. The most usual cause is a fault in the development of one or more sets of retinal cones that perceive colour in light and transmit that information to the optic nerve. This type of colour blindness is usually a sex-linked condition.
[14] Forged documents are detected by –
A.
ultraviolet rays
B.
infra-red rays
C.
beta rays
D.
gamma rays
Ans:
ultraviolet rays
Explanation :
Old postcards, books, signs, photos and other paper products made before the late 1930s rarely glow under a black light. Chemical bleaches and dyes used in modern papers will fluoresce under ultraviolet light. Knowing this helps to detect forged documents and distinguish reproductions in all types of ephemera.
[15] In which medium, velocity of sound is maximum?
A.
Metals
B.
Air
C.
Water
D.
Polymer
Ans:
Metals
Explanation :
The speed of sound is highest in solid. The speed of sound depends on the density of the medium through which it is travelling.
[16] If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same -
A.
velocity
B.
momentum
C.
acceleration
D.
kinetic energy
Ans:
momentum
Explanation :
If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same momentum.
[17] The compound of a metal found in nature is called -
A.
Mineral
B.
Ore
C.
Flux
D.
Slag
Ans:
Mineral
Explanation :
Metals are an integral part of our planet and are found in almost all rocks and soils. Most metals form compounds called minerals, which are naturally occurring, inorganic solids with regular chemical compositions and crystal structures.
[18] Decibel is used to measure the intensity of -
A.
Magnetic field
B.
Sound
C.
Light
D.
Heat
Ans:
Sound
Explanation :
The decibel (abbreviated dB) is the unit used to measure the intensity of a sound. The decibel scale is a little odd because the human ear is incredibly sensitive. Our ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine. The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. The decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory.
[19] Rainbow is seen after rain because of hanging molecules of water which act as –
A.
lenses
B.
mirrors
C.
(2) prisms
D.
slabs
Ans:
mirrors
Explanation :
In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. In a rainbow, raindrops in the air act as tiny prisms. Light enters the raindrop, reflects off of the side of the drop and exits. In the process, it is broken into a spectrum just like it is in a triangular glass prism.
[20] Which of the following is a result of Surface tension?
A.
Gravitational pull
B.
Viscosity
C.
Capillary action
D.
Radiation
Ans:
Capillary action
Explanation :
Capillary action is the result of adhesion and surface tension. Adhesion of water to the walls of a vessel will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. The surface tension acts to hold the surface intact, so instead of just the edges moving upward, the whole liquid surface is dragged upward.
[21] Water is used in car radiator because of its –
A.
low density
B.
easy availability
C.
high specific heat capacity
D.
low boiling point
Ans:
high specific heat capacity
Explanation :
Water is used in car radiators because the Specific heat capacity of water is high as a result of which it takes away the heat from engine better compared to other liquids. This is a form of coolant used in the radiator. If the radiator was to overheat the car would come to a stop.
[22] If a metal can be drawn into wires relatively easily it is called:
A.
malleable
B.
ductile
C.
extractive
D.
tactile
Ans:
ductile
Explanation :
Ductility is a physical property of a material associated with the ability to be hammered thin or stretched into wire without breaking.
[23] At what temperature a body will not radiate any heat energy?
A.
0° C
B.
273° C
C.
100° C
D.
-273° C
Ans:
-273° C
Explanation :
All physical bodies with temperature over absolute zero (0 K or − 273°C) radiate energy in the form of electromagnetic waves.
[24] The mirror used for the head light of a car is –
A.
spherical concave
B.
plane
C.
cylindrical
D.
parabolic concave
Ans:
parabolic concave
Explanation :
Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.
[25] Knot is a measure of -
A.
Unit of speed
B.
the curvature of spherical objects
C.
solar radiation
D.
intensiry of earthquake shock
Ans:
Unit of speed
Explanation :
The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.
Explanation :
Species is the basic unit for understanding taxonomy, that occupies a key position. It is defined as a dynamic genetically distinct group of organisms, which resemble each other in all respect and freely interbreed among themselves to produce fertile offsprings.
[6] Light from the Sun reaches us in nearly -
A.
2 minutes
B.
4 minutes
C.
8 minutes
D.
16 minutes
Ans:
8 minutes
Explanation :
The sun's light takes about 8 minutes to reach the Earth after it has been emitted from the sun's surface. The time it takes for light to reach planets in our Solar System (not the Milky Way, which is our galaxy) varies from about 3 minutes for Mercury, to about 5.3 hours for Pluto
[7] A concave lens always forms an image which is –
A.
Real and erect
B.
Virtual and erect
C.
Real and inverted
D.
Virtual and inverted
Ans:
Virtual and erect
Explanation :
Concave lens possesses at least one surface that curves inwards. It is a diverging lens, spreading out those light rays that have been refracted through it. A concave lens is thinner at its centre than at its edges, and is used to correct short-sightedness (myopia). After light rays have passed through the lens, they appear to come from a point called the principal focus. The image formed by a concave lens is virtual, upright, and smaller than the object, and it cannot be projected onto a screen.
[8] One can distinguish a telescope from a microscope by observing –
A.
length
B.
colour
C.
size of the lens
D.
length and size of the lens
Ans:
length and size of the lens
Explanation :
Telescope and Microscope are two scientific instruments that serve their purposes differently. One of the main differences between a telescope and a microscope is that a telescope is used to view things that are far whereas a microscope is used to view things that are very near. Another important difference between telescope and microscope is that the focal length or the distance from the focal point to the lens is different in these two scientific instruments.
[9] The sound produced by a bat is –
A.
audible
B.
subsonic
C.
infrasonic
D.
ultrasonic
Ans:
ultrasonic
Explanation :
Although bats use echolocation to detect their prey, and find their way around in the dark, the sounds which they emit are 'ultrasonic', which is another way of saying they are beyond the range of normal human hearing. Ultrasound is a cyclic sound pressure wave with a frequency greater than the upper limit of the human hearing range. Ultrasound is thus not separated from "normal" (audible) sound based on differences in physical properties, only the fact that humans cannot hear it.
[10] The image of an object formed on the retina of the eye is -
A.
virtual and upright
B.
virtual and inverted
C.
real and inverted
D.
Real and upright
Ans:
real and inverted
Explanation :
The retina is the thin light-sensitive membrane lining the inner eyeball towards the back of the eye. When the light goes into the eye it must pass through the lens (a biconvex lens), which inverts the image we are seeing. When we look at an image, light bounces it into our eye. As it enters our eye and passes through the lens the image gets inverted- reversed and flipped the other way- so that the image on our retina looks like an upside down object going from right to left instead of left to right. Once this image is set on the retina, cone cells distinguish the colour and detail, while rod cells distinguish movement and shades of grey.
[11] In a nuclear reactor, one of the following is used as a fuel.
A.
Coal
B.
Uranium
C.
Radium
D.
Diesel
Ans:
Uranium
Explanation :
Many contemporary uses of uranium exploit its unique nuclear properties. Uranium-235 has the distinction of being the only naturally occurring fissile isotope. Uranium-238 is fissionable by fast neutrons, and is fertile, meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor. Another fissile isotope, uranium-233, can be produced from natural thorium and is also important in nuclear technology.
[12] Suns heat reaches us by –
A.
Conduction
B.
Convection
C.
Radiation
D.
Reflection
Ans:
Radiation
Explanation :
Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. The sun's rays reach us in the form of electromagnetic radiation. This type of radiation covers a wide spectrum (that is a wide range of frequencies), but those from the sun are mainly infra-red, visible, and ultraviolet.
[13] A colour-blind person cannot –
A.
See distant objects
B.
See black colour
C.
Distinguish between certain colours
D.
Have persistence of vision
Ans:
Distinguish between certain colours
Explanation :
Colour blindness or colour vision deficiency is the inability or decreased ability to see coluor, or perceive colour differences, under normal lighting conditions. The most usual cause is a fault in the development of one or more sets of retinal cones that perceive colour in light and transmit that information to the optic nerve. This type of colour blindness is usually a sex-linked condition.
[14] Forged documents are detected by –
A.
ultraviolet rays
B.
infra-red rays
C.
beta rays
D.
gamma rays
Ans:
ultraviolet rays
Explanation :
Old postcards, books, signs, photos and other paper products made before the late 1930s rarely glow under a black light. Chemical bleaches and dyes used in modern papers will fluoresce under ultraviolet light. Knowing this helps to detect forged documents and distinguish reproductions in all types of ephemera.
[15] In which medium, velocity of sound is maximum?
A.
Metals
B.
Air
C.
Water
D.
Polymer
Ans:
Metals
Explanation :
The speed of sound is highest in solid. The speed of sound depends on the density of the medium through which it is travelling.
[16] If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same -
A.
velocity
B.
momentum
C.
acceleration
D.
kinetic energy
Ans:
momentum
Explanation :
If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same momentum.
[17] The compound of a metal found in nature is called -
A.
Mineral
B.
Ore
C.
Flux
D.
Slag
Ans:
Mineral
Explanation :
Metals are an integral part of our planet and are found in almost all rocks and soils. Most metals form compounds called minerals, which are naturally occurring, inorganic solids with regular chemical compositions and crystal structures.
[18] Decibel is used to measure the intensity of -
A.
Magnetic field
B.
Sound
C.
Light
D.
Heat
Ans:
Sound
Explanation :
The decibel (abbreviated dB) is the unit used to measure the intensity of a sound. The decibel scale is a little odd because the human ear is incredibly sensitive. Our ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine. The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. The decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory.
[19] Rainbow is seen after rain because of hanging molecules of water which act as –
A.
lenses
B.
mirrors
C.
(2) prisms
D.
slabs
Ans:
mirrors
Explanation :
In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. In a rainbow, raindrops in the air act as tiny prisms. Light enters the raindrop, reflects off of the side of the drop and exits. In the process, it is broken into a spectrum just like it is in a triangular glass prism.
[20] Which of the following is a result of Surface tension?
A.
Gravitational pull
B.
Viscosity
C.
Capillary action
D.
Radiation
Ans:
Capillary action
Explanation :
Capillary action is the result of adhesion and surface tension. Adhesion of water to the walls of a vessel will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. The surface tension acts to hold the surface intact, so instead of just the edges moving upward, the whole liquid surface is dragged upward.
[21] Water is used in car radiator because of its –
A.
low density
B.
easy availability
C.
high specific heat capacity
D.
low boiling point
Ans:
high specific heat capacity
Explanation :
Water is used in car radiators because the Specific heat capacity of water is high as a result of which it takes away the heat from engine better compared to other liquids. This is a form of coolant used in the radiator. If the radiator was to overheat the car would come to a stop.
[22] If a metal can be drawn into wires relatively easily it is called:
A.
malleable
B.
ductile
C.
extractive
D.
tactile
Ans:
ductile
Explanation :
Ductility is a physical property of a material associated with the ability to be hammered thin or stretched into wire without breaking.
[23] At what temperature a body will not radiate any heat energy?
A.
0° C
B.
273° C
C.
100° C
D.
-273° C
Ans:
-273° C
Explanation :
All physical bodies with temperature over absolute zero (0 K or − 273°C) radiate energy in the form of electromagnetic waves.
[24] The mirror used for the head light of a car is –
A.
spherical concave
B.
plane
C.
cylindrical
D.
parabolic concave
Ans:
parabolic concave
Explanation :
Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.
[25] Knot is a measure of -
A.
Unit of speed
B.
the curvature of spherical objects
C.
solar radiation
D.
intensiry of earthquake shock
Ans:
Unit of speed
Explanation :
The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.
Explanation :
Concave lens possesses at least one surface that curves inwards. It is a diverging lens, spreading out those light rays that have been refracted through it. A concave lens is thinner at its centre than at its edges, and is used to correct short-sightedness (myopia). After light rays have passed through the lens, they appear to come from a point called the principal focus. The image formed by a concave lens is virtual, upright, and smaller than the object, and it cannot be projected onto a screen.
[8] One can distinguish a telescope from a microscope by observing –
A.
length
B.
colour
C.
size of the lens
D.
length and size of the lens
Ans:
length and size of the lens
Explanation :
Telescope and Microscope are two scientific instruments that serve their purposes differently. One of the main differences between a telescope and a microscope is that a telescope is used to view things that are far whereas a microscope is used to view things that are very near. Another important difference between telescope and microscope is that the focal length or the distance from the focal point to the lens is different in these two scientific instruments.
[9] The sound produced by a bat is –
A.
audible
B.
subsonic
C.
infrasonic
D.
ultrasonic
Ans:
ultrasonic
Explanation :
Although bats use echolocation to detect their prey, and find their way around in the dark, the sounds which they emit are 'ultrasonic', which is another way of saying they are beyond the range of normal human hearing. Ultrasound is a cyclic sound pressure wave with a frequency greater than the upper limit of the human hearing range. Ultrasound is thus not separated from "normal" (audible) sound based on differences in physical properties, only the fact that humans cannot hear it.
[10] The image of an object formed on the retina of the eye is -
A.
virtual and upright
B.
virtual and inverted
C.
real and inverted
D.
Real and upright
Ans:
real and inverted
Explanation :
The retina is the thin light-sensitive membrane lining the inner eyeball towards the back of the eye. When the light goes into the eye it must pass through the lens (a biconvex lens), which inverts the image we are seeing. When we look at an image, light bounces it into our eye. As it enters our eye and passes through the lens the image gets inverted- reversed and flipped the other way- so that the image on our retina looks like an upside down object going from right to left instead of left to right. Once this image is set on the retina, cone cells distinguish the colour and detail, while rod cells distinguish movement and shades of grey.
[11] In a nuclear reactor, one of the following is used as a fuel.
A.
Coal
B.
Uranium
C.
Radium
D.
Diesel
Ans:
Uranium
Explanation :
Many contemporary uses of uranium exploit its unique nuclear properties. Uranium-235 has the distinction of being the only naturally occurring fissile isotope. Uranium-238 is fissionable by fast neutrons, and is fertile, meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor. Another fissile isotope, uranium-233, can be produced from natural thorium and is also important in nuclear technology.
[12] Suns heat reaches us by –
A.
Conduction
B.
Convection
C.
Radiation
D.
Reflection
Ans:
Radiation
Explanation :
Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. The sun's rays reach us in the form of electromagnetic radiation. This type of radiation covers a wide spectrum (that is a wide range of frequencies), but those from the sun are mainly infra-red, visible, and ultraviolet.
[13] A colour-blind person cannot –
A.
See distant objects
B.
See black colour
C.
Distinguish between certain colours
D.
Have persistence of vision
Ans:
Distinguish between certain colours
Explanation :
Colour blindness or colour vision deficiency is the inability or decreased ability to see coluor, or perceive colour differences, under normal lighting conditions. The most usual cause is a fault in the development of one or more sets of retinal cones that perceive colour in light and transmit that information to the optic nerve. This type of colour blindness is usually a sex-linked condition.
[14] Forged documents are detected by –
A.
ultraviolet rays
B.
infra-red rays
C.
beta rays
D.
gamma rays
Ans:
ultraviolet rays
Explanation :
Old postcards, books, signs, photos and other paper products made before the late 1930s rarely glow under a black light. Chemical bleaches and dyes used in modern papers will fluoresce under ultraviolet light. Knowing this helps to detect forged documents and distinguish reproductions in all types of ephemera.
[15] In which medium, velocity of sound is maximum?
A.
Metals
B.
Air
C.
Water
D.
Polymer
Ans:
Metals
Explanation :
The speed of sound is highest in solid. The speed of sound depends on the density of the medium through which it is travelling.
[16] If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same -
A.
velocity
B.
momentum
C.
acceleration
D.
kinetic energy
Ans:
momentum
Explanation :
If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same momentum.
[17] The compound of a metal found in nature is called -
A.
Mineral
B.
Ore
C.
Flux
D.
Slag
Ans:
Mineral
Explanation :
Metals are an integral part of our planet and are found in almost all rocks and soils. Most metals form compounds called minerals, which are naturally occurring, inorganic solids with regular chemical compositions and crystal structures.
[18] Decibel is used to measure the intensity of -
A.
Magnetic field
B.
Sound
C.
Light
D.
Heat
Ans:
Sound
Explanation :
The decibel (abbreviated dB) is the unit used to measure the intensity of a sound. The decibel scale is a little odd because the human ear is incredibly sensitive. Our ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine. The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. The decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory.
[19] Rainbow is seen after rain because of hanging molecules of water which act as –
A.
lenses
B.
mirrors
C.
(2) prisms
D.
slabs
Ans:
mirrors
Explanation :
In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. In a rainbow, raindrops in the air act as tiny prisms. Light enters the raindrop, reflects off of the side of the drop and exits. In the process, it is broken into a spectrum just like it is in a triangular glass prism.
[20] Which of the following is a result of Surface tension?
A.
Gravitational pull
B.
Viscosity
C.
Capillary action
D.
Radiation
Ans:
Capillary action
Explanation :
Capillary action is the result of adhesion and surface tension. Adhesion of water to the walls of a vessel will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. The surface tension acts to hold the surface intact, so instead of just the edges moving upward, the whole liquid surface is dragged upward.
[21] Water is used in car radiator because of its –
A.
low density
B.
easy availability
C.
high specific heat capacity
D.
low boiling point
Ans:
high specific heat capacity
Explanation :
Water is used in car radiators because the Specific heat capacity of water is high as a result of which it takes away the heat from engine better compared to other liquids. This is a form of coolant used in the radiator. If the radiator was to overheat the car would come to a stop.
[22] If a metal can be drawn into wires relatively easily it is called:
A.
malleable
B.
ductile
C.
extractive
D.
tactile
Ans:
ductile
Explanation :
Ductility is a physical property of a material associated with the ability to be hammered thin or stretched into wire without breaking.
[23] At what temperature a body will not radiate any heat energy?
A.
0° C
B.
273° C
C.
100° C
D.
-273° C
Ans:
-273° C
Explanation :
All physical bodies with temperature over absolute zero (0 K or − 273°C) radiate energy in the form of electromagnetic waves.
[24] The mirror used for the head light of a car is –
A.
spherical concave
B.
plane
C.
cylindrical
D.
parabolic concave
Ans:
parabolic concave
Explanation :
Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.
[25] Knot is a measure of -
A.
Unit of speed
B.
the curvature of spherical objects
C.
solar radiation
D.
intensiry of earthquake shock
Ans:
Unit of speed
Explanation :
The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.
Explanation :
Although bats use echolocation to detect their prey, and find their way around in the dark, the sounds which they emit are 'ultrasonic', which is another way of saying they are beyond the range of normal human hearing. Ultrasound is a cyclic sound pressure wave with a frequency greater than the upper limit of the human hearing range. Ultrasound is thus not separated from "normal" (audible) sound based on differences in physical properties, only the fact that humans cannot hear it.
[10] The image of an object formed on the retina of the eye is -
A.
virtual and upright
B.
virtual and inverted
C.
real and inverted
D.
Real and upright
Ans:
real and inverted
Explanation :
The retina is the thin light-sensitive membrane lining the inner eyeball towards the back of the eye. When the light goes into the eye it must pass through the lens (a biconvex lens), which inverts the image we are seeing. When we look at an image, light bounces it into our eye. As it enters our eye and passes through the lens the image gets inverted- reversed and flipped the other way- so that the image on our retina looks like an upside down object going from right to left instead of left to right. Once this image is set on the retina, cone cells distinguish the colour and detail, while rod cells distinguish movement and shades of grey.
[11] In a nuclear reactor, one of the following is used as a fuel.
A.
Coal
B.
Uranium
C.
Radium
D.
Diesel
Ans:
Uranium
Explanation :
Many contemporary uses of uranium exploit its unique nuclear properties. Uranium-235 has the distinction of being the only naturally occurring fissile isotope. Uranium-238 is fissionable by fast neutrons, and is fertile, meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor. Another fissile isotope, uranium-233, can be produced from natural thorium and is also important in nuclear technology.
[12] Suns heat reaches us by –
A.
Conduction
B.
Convection
C.
Radiation
D.
Reflection
Ans:
Radiation
Explanation :
Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. The sun's rays reach us in the form of electromagnetic radiation. This type of radiation covers a wide spectrum (that is a wide range of frequencies), but those from the sun are mainly infra-red, visible, and ultraviolet.
[13] A colour-blind person cannot –
A.
See distant objects
B.
See black colour
C.
Distinguish between certain colours
D.
Have persistence of vision
Ans:
Distinguish between certain colours
Explanation :
Colour blindness or colour vision deficiency is the inability or decreased ability to see coluor, or perceive colour differences, under normal lighting conditions. The most usual cause is a fault in the development of one or more sets of retinal cones that perceive colour in light and transmit that information to the optic nerve. This type of colour blindness is usually a sex-linked condition.
[14] Forged documents are detected by –
A.
ultraviolet rays
B.
infra-red rays
C.
beta rays
D.
gamma rays
Ans:
ultraviolet rays
Explanation :
Old postcards, books, signs, photos and other paper products made before the late 1930s rarely glow under a black light. Chemical bleaches and dyes used in modern papers will fluoresce under ultraviolet light. Knowing this helps to detect forged documents and distinguish reproductions in all types of ephemera.
[15] In which medium, velocity of sound is maximum?
A.
Metals
B.
Air
C.
Water
D.
Polymer
Ans:
Metals
Explanation :
The speed of sound is highest in solid. The speed of sound depends on the density of the medium through which it is travelling.
[16] If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same -
A.
velocity
B.
momentum
C.
acceleration
D.
kinetic energy
Ans:
momentum
Explanation :
If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same momentum.
[17] The compound of a metal found in nature is called -
A.
Mineral
B.
Ore
C.
Flux
D.
Slag
Ans:
Mineral
Explanation :
Metals are an integral part of our planet and are found in almost all rocks and soils. Most metals form compounds called minerals, which are naturally occurring, inorganic solids with regular chemical compositions and crystal structures.
[18] Decibel is used to measure the intensity of -
A.
Magnetic field
B.
Sound
C.
Light
D.
Heat
Ans:
Sound
Explanation :
The decibel (abbreviated dB) is the unit used to measure the intensity of a sound. The decibel scale is a little odd because the human ear is incredibly sensitive. Our ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine. The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. The decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory.
[19] Rainbow is seen after rain because of hanging molecules of water which act as –
A.
lenses
B.
mirrors
C.
(2) prisms
D.
slabs
Ans:
mirrors
Explanation :
In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. In a rainbow, raindrops in the air act as tiny prisms. Light enters the raindrop, reflects off of the side of the drop and exits. In the process, it is broken into a spectrum just like it is in a triangular glass prism.
[20] Which of the following is a result of Surface tension?
A.
Gravitational pull
B.
Viscosity
C.
Capillary action
D.
Radiation
Ans:
Capillary action
Explanation :
Capillary action is the result of adhesion and surface tension. Adhesion of water to the walls of a vessel will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. The surface tension acts to hold the surface intact, so instead of just the edges moving upward, the whole liquid surface is dragged upward.
[21] Water is used in car radiator because of its –
A.
low density
B.
easy availability
C.
high specific heat capacity
D.
low boiling point
Ans:
high specific heat capacity
Explanation :
Water is used in car radiators because the Specific heat capacity of water is high as a result of which it takes away the heat from engine better compared to other liquids. This is a form of coolant used in the radiator. If the radiator was to overheat the car would come to a stop.
[22] If a metal can be drawn into wires relatively easily it is called:
A.
malleable
B.
ductile
C.
extractive
D.
tactile
Ans:
ductile
Explanation :
Ductility is a physical property of a material associated with the ability to be hammered thin or stretched into wire without breaking.
[23] At what temperature a body will not radiate any heat energy?
A.
0° C
B.
273° C
C.
100° C
D.
-273° C
Ans:
-273° C
Explanation :
All physical bodies with temperature over absolute zero (0 K or − 273°C) radiate energy in the form of electromagnetic waves.
[24] The mirror used for the head light of a car is –
A.
spherical concave
B.
plane
C.
cylindrical
D.
parabolic concave
Ans:
parabolic concave
Explanation :
Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.
[25] Knot is a measure of -
A.
Unit of speed
B.
the curvature of spherical objects
C.
solar radiation
D.
intensiry of earthquake shock
Ans:
Unit of speed
Explanation :
The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.
Explanation :
Many contemporary uses of uranium exploit its unique nuclear properties. Uranium-235 has the distinction of being the only naturally occurring fissile isotope. Uranium-238 is fissionable by fast neutrons, and is fertile, meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor. Another fissile isotope, uranium-233, can be produced from natural thorium and is also important in nuclear technology.
[12] Suns heat reaches us by –
A.
Conduction
B.
Convection
C.
Radiation
D.
Reflection
Ans:
Radiation
Explanation :
Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. The sun's rays reach us in the form of electromagnetic radiation. This type of radiation covers a wide spectrum (that is a wide range of frequencies), but those from the sun are mainly infra-red, visible, and ultraviolet.
[13] A colour-blind person cannot –
A.
See distant objects
B.
See black colour
C.
Distinguish between certain colours
D.
Have persistence of vision
Ans:
Distinguish between certain colours
Explanation :
Colour blindness or colour vision deficiency is the inability or decreased ability to see coluor, or perceive colour differences, under normal lighting conditions. The most usual cause is a fault in the development of one or more sets of retinal cones that perceive colour in light and transmit that information to the optic nerve. This type of colour blindness is usually a sex-linked condition.
[14] Forged documents are detected by –
A.
ultraviolet rays
B.
infra-red rays
C.
beta rays
D.
gamma rays
Ans:
ultraviolet rays
Explanation :
Old postcards, books, signs, photos and other paper products made before the late 1930s rarely glow under a black light. Chemical bleaches and dyes used in modern papers will fluoresce under ultraviolet light. Knowing this helps to detect forged documents and distinguish reproductions in all types of ephemera.
[15] In which medium, velocity of sound is maximum?
A.
Metals
B.
Air
C.
Water
D.
Polymer
Ans:
Metals
Explanation :
The speed of sound is highest in solid. The speed of sound depends on the density of the medium through which it is travelling.
[16] If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same -
A.
velocity
B.
momentum
C.
acceleration
D.
kinetic energy
Ans:
momentum
Explanation :
If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same momentum.
[17] The compound of a metal found in nature is called -
A.
Mineral
B.
Ore
C.
Flux
D.
Slag
Ans:
Mineral
Explanation :
Metals are an integral part of our planet and are found in almost all rocks and soils. Most metals form compounds called minerals, which are naturally occurring, inorganic solids with regular chemical compositions and crystal structures.
[18] Decibel is used to measure the intensity of -
A.
Magnetic field
B.
Sound
C.
Light
D.
Heat
Ans:
Sound
Explanation :
The decibel (abbreviated dB) is the unit used to measure the intensity of a sound. The decibel scale is a little odd because the human ear is incredibly sensitive. Our ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine. The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. The decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory.
[19] Rainbow is seen after rain because of hanging molecules of water which act as –
A.
lenses
B.
mirrors
C.
(2) prisms
D.
slabs
Ans:
mirrors
Explanation :
In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. In a rainbow, raindrops in the air act as tiny prisms. Light enters the raindrop, reflects off of the side of the drop and exits. In the process, it is broken into a spectrum just like it is in a triangular glass prism.
[20] Which of the following is a result of Surface tension?
A.
Gravitational pull
B.
Viscosity
C.
Capillary action
D.
Radiation
Ans:
Capillary action
Explanation :
Capillary action is the result of adhesion and surface tension. Adhesion of water to the walls of a vessel will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. The surface tension acts to hold the surface intact, so instead of just the edges moving upward, the whole liquid surface is dragged upward.
[21] Water is used in car radiator because of its –
A.
low density
B.
easy availability
C.
high specific heat capacity
D.
low boiling point
Ans:
high specific heat capacity
Explanation :
Water is used in car radiators because the Specific heat capacity of water is high as a result of which it takes away the heat from engine better compared to other liquids. This is a form of coolant used in the radiator. If the radiator was to overheat the car would come to a stop.
[22] If a metal can be drawn into wires relatively easily it is called:
A.
malleable
B.
ductile
C.
extractive
D.
tactile
Ans:
ductile
Explanation :
Ductility is a physical property of a material associated with the ability to be hammered thin or stretched into wire without breaking.
[23] At what temperature a body will not radiate any heat energy?
A.
0° C
B.
273° C
C.
100° C
D.
-273° C
Ans:
-273° C
Explanation :
All physical bodies with temperature over absolute zero (0 K or − 273°C) radiate energy in the form of electromagnetic waves.
[24] The mirror used for the head light of a car is –
A.
spherical concave
B.
plane
C.
cylindrical
D.
parabolic concave
Ans:
parabolic concave
Explanation :
Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.
[25] Knot is a measure of -
A.
Unit of speed
B.
the curvature of spherical objects
C.
solar radiation
D.
intensiry of earthquake shock
Ans:
Unit of speed
Explanation :
The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.
Explanation :
Colour blindness or colour vision deficiency is the inability or decreased ability to see coluor, or perceive colour differences, under normal lighting conditions. The most usual cause is a fault in the development of one or more sets of retinal cones that perceive colour in light and transmit that information to the optic nerve. This type of colour blindness is usually a sex-linked condition.
[14] Forged documents are detected by –
A.
ultraviolet rays
B.
infra-red rays
C.
beta rays
D.
gamma rays
Ans:
ultraviolet rays
Explanation :
Old postcards, books, signs, photos and other paper products made before the late 1930s rarely glow under a black light. Chemical bleaches and dyes used in modern papers will fluoresce under ultraviolet light. Knowing this helps to detect forged documents and distinguish reproductions in all types of ephemera.
[15] In which medium, velocity of sound is maximum?
A.
Metals
B.
Air
C.
Water
D.
Polymer
Ans:
Metals
Explanation :
The speed of sound is highest in solid. The speed of sound depends on the density of the medium through which it is travelling.
[16] If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same -
A.
velocity
B.
momentum
C.
acceleration
D.
kinetic energy
Ans:
momentum
Explanation :
If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same momentum.
[17] The compound of a metal found in nature is called -
A.
Mineral
B.
Ore
C.
Flux
D.
Slag
Ans:
Mineral
Explanation :
Metals are an integral part of our planet and are found in almost all rocks and soils. Most metals form compounds called minerals, which are naturally occurring, inorganic solids with regular chemical compositions and crystal structures.
[18] Decibel is used to measure the intensity of -
A.
Magnetic field
B.
Sound
C.
Light
D.
Heat
Ans:
Sound
Explanation :
The decibel (abbreviated dB) is the unit used to measure the intensity of a sound. The decibel scale is a little odd because the human ear is incredibly sensitive. Our ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine. The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. The decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory.
[19] Rainbow is seen after rain because of hanging molecules of water which act as –
A.
lenses
B.
mirrors
C.
(2) prisms
D.
slabs
Ans:
mirrors
Explanation :
In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. In a rainbow, raindrops in the air act as tiny prisms. Light enters the raindrop, reflects off of the side of the drop and exits. In the process, it is broken into a spectrum just like it is in a triangular glass prism.
[20] Which of the following is a result of Surface tension?
A.
Gravitational pull
B.
Viscosity
C.
Capillary action
D.
Radiation
Ans:
Capillary action
Explanation :
Capillary action is the result of adhesion and surface tension. Adhesion of water to the walls of a vessel will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. The surface tension acts to hold the surface intact, so instead of just the edges moving upward, the whole liquid surface is dragged upward.
[21] Water is used in car radiator because of its –
A.
low density
B.
easy availability
C.
high specific heat capacity
D.
low boiling point
Ans:
high specific heat capacity
Explanation :
Water is used in car radiators because the Specific heat capacity of water is high as a result of which it takes away the heat from engine better compared to other liquids. This is a form of coolant used in the radiator. If the radiator was to overheat the car would come to a stop.
[22] If a metal can be drawn into wires relatively easily it is called:
A.
malleable
B.
ductile
C.
extractive
D.
tactile
Ans:
ductile
Explanation :
Ductility is a physical property of a material associated with the ability to be hammered thin or stretched into wire without breaking.
[23] At what temperature a body will not radiate any heat energy?
A.
0° C
B.
273° C
C.
100° C
D.
-273° C
Ans:
-273° C
Explanation :
All physical bodies with temperature over absolute zero (0 K or − 273°C) radiate energy in the form of electromagnetic waves.
[24] The mirror used for the head light of a car is –
A.
spherical concave
B.
plane
C.
cylindrical
D.
parabolic concave
Ans:
parabolic concave
Explanation :
Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.
[25] Knot is a measure of -
A.
Unit of speed
B.
the curvature of spherical objects
C.
solar radiation
D.
intensiry of earthquake shock
Ans:
Unit of speed
Explanation :
The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.
Explanation :
The speed of sound is highest in solid. The speed of sound depends on the density of the medium through which it is travelling.
[16] If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same -
A.
velocity
B.
momentum
C.
acceleration
D.
kinetic energy
Ans:
momentum
Explanation :
If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same momentum.
[17] The compound of a metal found in nature is called -
A.
Mineral
B.
Ore
C.
Flux
D.
Slag
Ans:
Mineral
Explanation :
Metals are an integral part of our planet and are found in almost all rocks and soils. Most metals form compounds called minerals, which are naturally occurring, inorganic solids with regular chemical compositions and crystal structures.
[18] Decibel is used to measure the intensity of -
A.
Magnetic field
B.
Sound
C.
Light
D.
Heat
Ans:
Sound
Explanation :
The decibel (abbreviated dB) is the unit used to measure the intensity of a sound. The decibel scale is a little odd because the human ear is incredibly sensitive. Our ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine. The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. The decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory.
[19] Rainbow is seen after rain because of hanging molecules of water which act as –
A.
lenses
B.
mirrors
C.
(2) prisms
D.
slabs
Ans:
mirrors
Explanation :
In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. In a rainbow, raindrops in the air act as tiny prisms. Light enters the raindrop, reflects off of the side of the drop and exits. In the process, it is broken into a spectrum just like it is in a triangular glass prism.
[20] Which of the following is a result of Surface tension?
A.
Gravitational pull
B.
Viscosity
C.
Capillary action
D.
Radiation
Ans:
Capillary action
Explanation :
Capillary action is the result of adhesion and surface tension. Adhesion of water to the walls of a vessel will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. The surface tension acts to hold the surface intact, so instead of just the edges moving upward, the whole liquid surface is dragged upward.
[21] Water is used in car radiator because of its –
A.
low density
B.
easy availability
C.
high specific heat capacity
D.
low boiling point
Ans:
high specific heat capacity
Explanation :
Water is used in car radiators because the Specific heat capacity of water is high as a result of which it takes away the heat from engine better compared to other liquids. This is a form of coolant used in the radiator. If the radiator was to overheat the car would come to a stop.
[22] If a metal can be drawn into wires relatively easily it is called:
A.
malleable
B.
ductile
C.
extractive
D.
tactile
Ans:
ductile
Explanation :
Ductility is a physical property of a material associated with the ability to be hammered thin or stretched into wire without breaking.
[23] At what temperature a body will not radiate any heat energy?
A.
0° C
B.
273° C
C.
100° C
D.
-273° C
Ans:
-273° C
Explanation :
All physical bodies with temperature over absolute zero (0 K or − 273°C) radiate energy in the form of electromagnetic waves.
[24] The mirror used for the head light of a car is –
A.
spherical concave
B.
plane
C.
cylindrical
D.
parabolic concave
Ans:
parabolic concave
Explanation :
Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.
[25] Knot is a measure of -
A.
Unit of speed
B.
the curvature of spherical objects
C.
solar radiation
D.
intensiry of earthquake shock
Ans:
Unit of speed
Explanation :
The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.
Explanation :
Metals are an integral part of our planet and are found in almost all rocks and soils. Most metals form compounds called minerals, which are naturally occurring, inorganic solids with regular chemical compositions and crystal structures.
[18] Decibel is used to measure the intensity of -
A.
Magnetic field
B.
Sound
C.
Light
D.
Heat
Ans:
Sound
Explanation :
The decibel (abbreviated dB) is the unit used to measure the intensity of a sound. The decibel scale is a little odd because the human ear is incredibly sensitive. Our ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine. The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. The decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory.
[19] Rainbow is seen after rain because of hanging molecules of water which act as –
A.
lenses
B.
mirrors
C.
(2) prisms
D.
slabs
Ans:
mirrors
Explanation :
In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. In a rainbow, raindrops in the air act as tiny prisms. Light enters the raindrop, reflects off of the side of the drop and exits. In the process, it is broken into a spectrum just like it is in a triangular glass prism.
[20] Which of the following is a result of Surface tension?
A.
Gravitational pull
B.
Viscosity
C.
Capillary action
D.
Radiation
Ans:
Capillary action
Explanation :
Capillary action is the result of adhesion and surface tension. Adhesion of water to the walls of a vessel will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. The surface tension acts to hold the surface intact, so instead of just the edges moving upward, the whole liquid surface is dragged upward.
[21] Water is used in car radiator because of its –
A.
low density
B.
easy availability
C.
high specific heat capacity
D.
low boiling point
Ans:
high specific heat capacity
Explanation :
Water is used in car radiators because the Specific heat capacity of water is high as a result of which it takes away the heat from engine better compared to other liquids. This is a form of coolant used in the radiator. If the radiator was to overheat the car would come to a stop.
[22] If a metal can be drawn into wires relatively easily it is called:
A.
malleable
B.
ductile
C.
extractive
D.
tactile
Ans:
ductile
Explanation :
Ductility is a physical property of a material associated with the ability to be hammered thin or stretched into wire without breaking.
[23] At what temperature a body will not radiate any heat energy?
A.
0° C
B.
273° C
C.
100° C
D.
-273° C
Ans:
-273° C
Explanation :
All physical bodies with temperature over absolute zero (0 K or − 273°C) radiate energy in the form of electromagnetic waves.
[24] The mirror used for the head light of a car is –
A.
spherical concave
B.
plane
C.
cylindrical
D.
parabolic concave
Ans:
parabolic concave
Explanation :
Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.
[25] Knot is a measure of -
A.
Unit of speed
B.
the curvature of spherical objects
C.
solar radiation
D.
intensiry of earthquake shock
Ans:
Unit of speed
Explanation :
The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.
Explanation :
In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. In a rainbow, raindrops in the air act as tiny prisms. Light enters the raindrop, reflects off of the side of the drop and exits. In the process, it is broken into a spectrum just like it is in a triangular glass prism.
[20] Which of the following is a result of Surface tension?
A.
Gravitational pull
B.
Viscosity
C.
Capillary action
D.
Radiation
Ans:
Capillary action
Explanation :
Capillary action is the result of adhesion and surface tension. Adhesion of water to the walls of a vessel will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. The surface tension acts to hold the surface intact, so instead of just the edges moving upward, the whole liquid surface is dragged upward.
[21] Water is used in car radiator because of its –
A.
low density
B.
easy availability
C.
high specific heat capacity
D.
low boiling point
Ans:
high specific heat capacity
Explanation :
Water is used in car radiators because the Specific heat capacity of water is high as a result of which it takes away the heat from engine better compared to other liquids. This is a form of coolant used in the radiator. If the radiator was to overheat the car would come to a stop.
[22] If a metal can be drawn into wires relatively easily it is called:
A.
malleable
B.
ductile
C.
extractive
D.
tactile
Ans:
ductile
Explanation :
Ductility is a physical property of a material associated with the ability to be hammered thin or stretched into wire without breaking.
[23] At what temperature a body will not radiate any heat energy?
A.
0° C
B.
273° C
C.
100° C
D.
-273° C
Ans:
-273° C
Explanation :
All physical bodies with temperature over absolute zero (0 K or − 273°C) radiate energy in the form of electromagnetic waves.
[24] The mirror used for the head light of a car is –
A.
spherical concave
B.
plane
C.
cylindrical
D.
parabolic concave
Ans:
parabolic concave
Explanation :
Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.
[25] Knot is a measure of -
A.
Unit of speed
B.
the curvature of spherical objects
C.
solar radiation
D.
intensiry of earthquake shock
Ans:
Unit of speed
Explanation :
The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.
Explanation :
Water is used in car radiators because the Specific heat capacity of water is high as a result of which it takes away the heat from engine better compared to other liquids. This is a form of coolant used in the radiator. If the radiator was to overheat the car would come to a stop.
[22] If a metal can be drawn into wires relatively easily it is called:
A.
malleable
B.
ductile
C.
extractive
D.
tactile
Ans:
ductile
Explanation :
Ductility is a physical property of a material associated with the ability to be hammered thin or stretched into wire without breaking.
[23] At what temperature a body will not radiate any heat energy?
A.
0° C
B.
273° C
C.
100° C
D.
-273° C
Ans:
-273° C
Explanation :
All physical bodies with temperature over absolute zero (0 K or − 273°C) radiate energy in the form of electromagnetic waves.
[24] The mirror used for the head light of a car is –
A.
spherical concave
B.
plane
C.
cylindrical
D.
parabolic concave
Ans:
parabolic concave
Explanation :
Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.
[25] Knot is a measure of -
A.
Unit of speed
B.
the curvature of spherical objects
C.
solar radiation
D.
intensiry of earthquake shock
Ans:
Unit of speed
Explanation :
The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.
Explanation :
All physical bodies with temperature over absolute zero (0 K or − 273°C) radiate energy in the form of electromagnetic waves.
[24] The mirror used for the head light of a car is –
A.
spherical concave
B.
plane
C.
cylindrical
D.
parabolic concave
Ans:
parabolic concave
Explanation :
Car head lights have concave mirrors because it collects and focuses as much as possible of the light from the bulb and send it out as a fairly tight beam in one direction only. The bulb of the head light is placed at the focal point. The reflected light is parallel and gives more visibility to the driver at night.
[25] Knot is a measure of -
A.
Unit of speed
B.
the curvature of spherical objects
C.
solar radiation
D.
intensiry of earthquake shock
Ans:
Unit of speed
Explanation :
The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.
Explanation :
The knot (pronounced not) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. There is no standard abbreviation but km is commonly used. The knot is a non-SI unit accepted for use with the International System of Units (SI). Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels one minute of geographic latitude in one hour. The speeds of vessels relative to the fluids in which they travel (boat speeds and air speeds) are measured in knots.