[1] If you look into a mirror and find that the image (your reflexion) is smaller than you, then the type of the mirror is -
A.
plano-concave mirror
B.
concave mirror
C.
plane mirror
D.
convex mirror
Ans:
convex mirror
Explanation :
A convex mirror, diverging mirror, or fish eye mirror is a curved mirror in which the reflective surface bulges toward the light source. Such mirrors always form a virtual image and the image is smaller than the object.
[2] In an optical fibre the signal is transmitted –
A.
in a straight line path
B.
In a curved path
C.
due to total internal reflection
D.
Due to refraction
Ans:
due to total internal reflection
Explanation :
Total internal reflection is the basic concept be-hind the optical fiber. Optical fiber employs the trans- mission of light down fibers of plastic or glass. Because the fibers are thin, light entering one is likely to strike the inside surface at an angle greater than the critical angle and, thus, be totally reflected. In fact, most fibers have a varying refractive index to allow more light to be guided along the fiber through total internal refraction.
[3] At boiling point of liquids, its :
A.
Temperature increases
B.
Atmospheric pressure increases
C.
Timperature remains increases
D.
Vapour pressure decreases
Ans:
Timperature remains increases
Explanation :
An interesting property of matter is that its temperature remains constant during a phase change, assuming its surrounding pressure is constant. A liquid changes into gaseous state at a constant temperature called its boiling point. For example, when water is converted into vapors (gaseous state) at 100°C and so 100°C is its boiling point. The temperature remains constant at 100°C. The temperature of water increases only after all the water is evaporated. Likewise, once the temperature of a liquid is lowered to its freezing point, the temperature does not decrease until all the liquid has changed its phase to become a solid.
[4] Transformer is a device to convert –
A.
D.C. to A.C.
B.
Low voltage D.C. into high voltage D.C.
C.
Low voltage A.C. into high voltage A.C.
D.
Mechanical energy into Electrical energy
Ans:
Low voltage A.C. into high voltage A.C.
Explanation :
A transformer is an electrical device that transfers energy from one circuit to another by magnetic coupling with no moving parts. It converts high volt-age AC into low voltage AC and vice-versa.
[5] Two stones of unequal masses are thrown vertically up with the same velocity. Which of the following will happen?
A.
The heavier mass will reach greater height
B.
The lighter mass will reach greater height
C.
Both will reach the same height
D.
Any of them may reach greater height
Ans:
Both will reach the same height
Explanation :
Galileo's experiment showed that if two bodies of unequal masses are dropped from the same height, the time required by them to reach the ground are equal. If they are thrown vertically upwards with the same initial velocity, then the ratio of the time required to reach the ground is equal to unity. This means that both of them will reach the same height.
[6] Why does ice covered in sawdust ct melt quickly?
A.
Sawdust does not allow the air to touch the ice
B.
The water is absorbed by sawdust
C.
Sawdust is a bad conductor of heat
D.
Sawdust is good conductor of heat
Ans:
Sawdust is a bad conductor of heat
Explanation :
Ice needs to absorb heat energy to melt and become water (called latent heat of fusion). Since saw-dust is a poor conductor of heat, it takes more time for the ice to absorb the required heat energy. This allows ice to remain in solid state for more time when packed in saw dust.
[7] A man standing close to the platform at a railway station experiences a pulling force towards a fast moving train because of _.
A.
gravitational force between train and man.
B.
illusion of the man
C.
the centripetal force
D.
pressure difference due to fast moving air in between
Ans:
pressure difference due to fast moving air in between
Explanation :
When a fast-moving train passes a man standing on the platform at rest, the air between train and person also moves with greater speed. This rapidly moving air, by Bernoulli's principle will have a lower pressure than the still air a few feet away. The still air, having higher pressure, and being behind the man standing close will tend to push him toward the train.
[8] We feel cool when we sit near the fan, this is because –
A.
fan gives cool air.
B.
an cools surrounding air.
C.
air vapourises the sweat on our body.
D.
we feel cool when air touches the body.
Ans:
air vapourises the sweat on our body.
Explanation :
We feel comfortable sitting under a fan when we are perspiring because a fan increases the rate of evaporation of sweat (or moisture) from our body and makes us feel cool and comfortable.
[9] The average kinetic energy of the molecules of an ideal gas is directly proportional to –
A.
Velocity of Molecules
B.
Mass of Molecules
C.
Absolute temperature of the gas
D.
Temperature of environment
Ans:
Absolute temperature of the gas
Explanation :
The average kinetic energy of gas molecules is directly proportional to absolute temperature only. This implies that all molecular motion ceases if the temperature is reduced to absolute zero.
[10] When heated from 0°C to 100°C volume of a given mass of water will –
A.
Increase gradually
B.
Decrease gradually
C.
Increase and then will decrease
D.
Decrease and then will Increase
Ans:
Decrease and then will Increase
Explanation :
When heated from 00 to 100 C volume of a given mass of water will first decrease and then increase. If the word "ice" or "solid" is not mentioned, the word "water" means liquid water.
[11] Clothes keep us warm in winter because they :
A.
supply heat
B.
do not radiate heat
C.
prevent air from contacting the body
D.
prevent the heat of the body from escaping
Ans:
prevent the heat of the body from escaping
Explanation :
It is just because woolen clothes have fibres and between those fibres air is trapped which reduces heat loss. Air reduces heat loss because it is an insulator or poor conductor of heat. Hence, all the heat from our body gets trapped inside the clothes which makes us feels warmer with the clothes.
[12] In a refrigerator what produces the cooling?
A.
The ice which deposits on the freezer
B.
The sudden expansion of a compressed gas
C.
The evaporation of a volatile liquid
D.
None of these
Ans:
None of these
Explanation :
Basically, refrigeration system consists of devices that compress and expand refrigerant gas. When refrigerant gas is compressed it expels heat and when it is suddenly expanded, absorbs heat. A refrigerator (colloquially fridge) is a common household appliance that consists of a thermally insulated compartment and a heat pump (mechanical, electronic, or chemical) that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room.
[13] Microphone is a device which transforms the –
A.
sound signal into current signal
B.
current signal into sound signal
C.
sound signal into light signal
D.
light signal into sound signal
Ans:
sound signal into current signal
Explanation :
Microphone is a device which transforms the sound signal into current signal.
[14] Pressure Cooker cooks faster because –
A.
boiling point decreases with rise of pressure
B.
it cooks the food at low pressure
C.
higher temperature is attained for cooking
D.
the material of the cooker is a good conductor
Ans:
higher temperature is attained for cooking
Explanation :
In pressure cooker boiling point of water increases due to high pressure.
[15] What is a compound microscope?
A.
A microscope that has one lens.
B.
A microscope that has two sets of lenses : an occular lens and an eyepiece.
C.
A microscope whose lenses are concave.
D.
A microscope whose lenses are convex.
Ans:
A microscope that has two sets of lenses : an occular lens and an eyepiece.
Explanation :
A compound microscope is a microscope which uses multiple lenses to collect light from the sample and then a separate set of lenses to focus the light into the eye or camera. The objective lens provides the primary magnification which is compounded (multiplied) by the ocular lens (eyepiece).
[16] The temperature of boiling water in a steam engine may be high because -
A.
there are dissolved substances in water
B.
there is low pressure inside the boiler
C.
there is high pressure inside the boiler
D.
the lire is at very high temperature
Ans:
there is high pressure inside the boiler
Explanation :
In the boiler of a steam engine, there is a firebox where coal is shoveled into. The coal is kept burning at a very high temperature, and is used to heat the boiler to boil water producing a high pressure steam. The high-pressure steam expands and exits the boiler via steam pipes into the steam reservoir; the steam is then controlled by a slide valve to move into a cylinder to push the piston.
[17] The motion of a body around a circular path is an example of –
A.
Uniform velocity, variable acceleration
B.
Uniform speed, uniform velocity
C.
Uniform speed, variable velocity
D.
Uniform speed, variable acceleration
Ans:
Uniform velocity, variable acceleration
Explanation :
Uniform circular motion occurs when a body moves in a circular path with constant velocity.
[18] A gas thermometer is more sensitive than a liquid thermometer because a gas:
A.
is lighter than liquid
B.
expands more than a liquid
C.
is easy to obtain
D.
does not change state easily
Ans:
does not change state easily
Explanation :
Gas is easily compressed so it would have a more versatile range of measurement at least in our atmospheric conditions. Liquid is not so easily compressed, so, very little pressure via mass w/ gravity or heat would cause it to quickly jump between changes. A gas thermometer measures temperature by the variation in volume or pressure of a gas. One common apparatus is a constant volume thermometer. Gas thermometers are often used to calibrate other thermometers.
[19] Outside of cooking utensils are generally left black from below because –
A.
it is difficult to clean daily.
B.
black surface is a good conductor of heat.
C.
black surface is a poor conductor of heat.
D.
black surface is a good absorber of heat.
Ans:
black surface is a good absorber of heat.
Explanation :
The outside surface of a utensil used for heating is coated black so that it may absorb more heat and make heating quicker. This is because black surface is a good absorber of heat.
[20] X-rays region lies between –
A.
Ultraviolet and visible region
B.
Visible and infra-red region
C.
Gamma-rays and ultraviolet region
D.
Short radio waves and long radio waves
Ans:
Gamma-rays and ultraviolet region
Explanation :
X-rays region lies between Gamma rays and ultraviolet region.
[21] A star appears twinkling in the sky because of –
A.
scattering of light by atmosphere
B.
reflection of light by atmosphere
C.
refraction of light by atmosphere
D.
diffraction of light by atmosphere
Ans:
refraction of light by atmosphere
Explanation :
A star appears twinkling in the sky because of refraction of light, by atmosphere. Light bends when it passes obliquely from one medium to another. This is called refraction of light.
[22] Water pipes in hilly areas often burst on a cold frosty night, because –
A.
The material of which pipes are made contracts due to cold and so breaks
B.
Water in the pipes freezes and on freezing water expands, so pipes break
C.
Frost makes the pipes rusty, so they break
D.
None of these
Ans:
Water in the pipes freezes and on freezing water expands, so pipes break
Explanation :
The temperature may fall below 0° C during cold frosty nights which converts the water inside the pipes into ice, resulting in an increase in volume. This exerts great force on the pipes and as a result, they burst.
[23] A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because–
A.
Stone is heavier than parachute
B.
Special mechanisms are present in parachute
C.
A parachute has a larger surface area and air resistance is more
D.
None of these
Ans:
A parachute has a larger surface area and air resistance is more
Explanation :
Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more friction slowing him down because air resistance works against the very large surface area of the parachute. A free falling skydiver that has not yet opened his parachute can make his downward speed vary between about 110 mph and 225 mph-using air resistance.
[24] In electronics what comes under tank circuit?
A.
Resistance and capacity
B.
Resistance and inductance
C.
Capacity and inductance
D.
Resistance, capacity and inductance
Ans:
Capacity and inductance
Explanation :
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C. When connected together, they can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency.
[25] In the process of magnetization of a bar –
A.
The entire bulk of the bar gets magnetized
B.
Only the surface of the bar gets magnetized
C.
Only the ends of the bar get magnetized
D.
Only some parts of the outer layers of the bar get magnetized
Ans:
The entire bulk of the bar gets magnetized
Explanation :
In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized.
Explanation :
A convex mirror, diverging mirror, or fish eye mirror is a curved mirror in which the reflective surface bulges toward the light source. Such mirrors always form a virtual image and the image is smaller than the object.
[2] In an optical fibre the signal is transmitted –
A.
in a straight line path
B.
In a curved path
C.
due to total internal reflection
D.
Due to refraction
Ans:
due to total internal reflection
Explanation :
Total internal reflection is the basic concept be-hind the optical fiber. Optical fiber employs the trans- mission of light down fibers of plastic or glass. Because the fibers are thin, light entering one is likely to strike the inside surface at an angle greater than the critical angle and, thus, be totally reflected. In fact, most fibers have a varying refractive index to allow more light to be guided along the fiber through total internal refraction.
[3] At boiling point of liquids, its :
A.
Temperature increases
B.
Atmospheric pressure increases
C.
Timperature remains increases
D.
Vapour pressure decreases
Ans:
Timperature remains increases
Explanation :
An interesting property of matter is that its temperature remains constant during a phase change, assuming its surrounding pressure is constant. A liquid changes into gaseous state at a constant temperature called its boiling point. For example, when water is converted into vapors (gaseous state) at 100°C and so 100°C is its boiling point. The temperature remains constant at 100°C. The temperature of water increases only after all the water is evaporated. Likewise, once the temperature of a liquid is lowered to its freezing point, the temperature does not decrease until all the liquid has changed its phase to become a solid.
[4] Transformer is a device to convert –
A.
D.C. to A.C.
B.
Low voltage D.C. into high voltage D.C.
C.
Low voltage A.C. into high voltage A.C.
D.
Mechanical energy into Electrical energy
Ans:
Low voltage A.C. into high voltage A.C.
Explanation :
A transformer is an electrical device that transfers energy from one circuit to another by magnetic coupling with no moving parts. It converts high volt-age AC into low voltage AC and vice-versa.
[5] Two stones of unequal masses are thrown vertically up with the same velocity. Which of the following will happen?
A.
The heavier mass will reach greater height
B.
The lighter mass will reach greater height
C.
Both will reach the same height
D.
Any of them may reach greater height
Ans:
Both will reach the same height
Explanation :
Galileo's experiment showed that if two bodies of unequal masses are dropped from the same height, the time required by them to reach the ground are equal. If they are thrown vertically upwards with the same initial velocity, then the ratio of the time required to reach the ground is equal to unity. This means that both of them will reach the same height.
[6] Why does ice covered in sawdust ct melt quickly?
A.
Sawdust does not allow the air to touch the ice
B.
The water is absorbed by sawdust
C.
Sawdust is a bad conductor of heat
D.
Sawdust is good conductor of heat
Ans:
Sawdust is a bad conductor of heat
Explanation :
Ice needs to absorb heat energy to melt and become water (called latent heat of fusion). Since saw-dust is a poor conductor of heat, it takes more time for the ice to absorb the required heat energy. This allows ice to remain in solid state for more time when packed in saw dust.
[7] A man standing close to the platform at a railway station experiences a pulling force towards a fast moving train because of _.
A.
gravitational force between train and man.
B.
illusion of the man
C.
the centripetal force
D.
pressure difference due to fast moving air in between
Ans:
pressure difference due to fast moving air in between
Explanation :
When a fast-moving train passes a man standing on the platform at rest, the air between train and person also moves with greater speed. This rapidly moving air, by Bernoulli's principle will have a lower pressure than the still air a few feet away. The still air, having higher pressure, and being behind the man standing close will tend to push him toward the train.
[8] We feel cool when we sit near the fan, this is because –
A.
fan gives cool air.
B.
an cools surrounding air.
C.
air vapourises the sweat on our body.
D.
we feel cool when air touches the body.
Ans:
air vapourises the sweat on our body.
Explanation :
We feel comfortable sitting under a fan when we are perspiring because a fan increases the rate of evaporation of sweat (or moisture) from our body and makes us feel cool and comfortable.
[9] The average kinetic energy of the molecules of an ideal gas is directly proportional to –
A.
Velocity of Molecules
B.
Mass of Molecules
C.
Absolute temperature of the gas
D.
Temperature of environment
Ans:
Absolute temperature of the gas
Explanation :
The average kinetic energy of gas molecules is directly proportional to absolute temperature only. This implies that all molecular motion ceases if the temperature is reduced to absolute zero.
[10] When heated from 0°C to 100°C volume of a given mass of water will –
A.
Increase gradually
B.
Decrease gradually
C.
Increase and then will decrease
D.
Decrease and then will Increase
Ans:
Decrease and then will Increase
Explanation :
When heated from 00 to 100 C volume of a given mass of water will first decrease and then increase. If the word "ice" or "solid" is not mentioned, the word "water" means liquid water.
[11] Clothes keep us warm in winter because they :
A.
supply heat
B.
do not radiate heat
C.
prevent air from contacting the body
D.
prevent the heat of the body from escaping
Ans:
prevent the heat of the body from escaping
Explanation :
It is just because woolen clothes have fibres and between those fibres air is trapped which reduces heat loss. Air reduces heat loss because it is an insulator or poor conductor of heat. Hence, all the heat from our body gets trapped inside the clothes which makes us feels warmer with the clothes.
[12] In a refrigerator what produces the cooling?
A.
The ice which deposits on the freezer
B.
The sudden expansion of a compressed gas
C.
The evaporation of a volatile liquid
D.
None of these
Ans:
None of these
Explanation :
Basically, refrigeration system consists of devices that compress and expand refrigerant gas. When refrigerant gas is compressed it expels heat and when it is suddenly expanded, absorbs heat. A refrigerator (colloquially fridge) is a common household appliance that consists of a thermally insulated compartment and a heat pump (mechanical, electronic, or chemical) that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room.
[13] Microphone is a device which transforms the –
A.
sound signal into current signal
B.
current signal into sound signal
C.
sound signal into light signal
D.
light signal into sound signal
Ans:
sound signal into current signal
Explanation :
Microphone is a device which transforms the sound signal into current signal.
[14] Pressure Cooker cooks faster because –
A.
boiling point decreases with rise of pressure
B.
it cooks the food at low pressure
C.
higher temperature is attained for cooking
D.
the material of the cooker is a good conductor
Ans:
higher temperature is attained for cooking
Explanation :
In pressure cooker boiling point of water increases due to high pressure.
[15] What is a compound microscope?
A.
A microscope that has one lens.
B.
A microscope that has two sets of lenses : an occular lens and an eyepiece.
C.
A microscope whose lenses are concave.
D.
A microscope whose lenses are convex.
Ans:
A microscope that has two sets of lenses : an occular lens and an eyepiece.
Explanation :
A compound microscope is a microscope which uses multiple lenses to collect light from the sample and then a separate set of lenses to focus the light into the eye or camera. The objective lens provides the primary magnification which is compounded (multiplied) by the ocular lens (eyepiece).
[16] The temperature of boiling water in a steam engine may be high because -
A.
there are dissolved substances in water
B.
there is low pressure inside the boiler
C.
there is high pressure inside the boiler
D.
the lire is at very high temperature
Ans:
there is high pressure inside the boiler
Explanation :
In the boiler of a steam engine, there is a firebox where coal is shoveled into. The coal is kept burning at a very high temperature, and is used to heat the boiler to boil water producing a high pressure steam. The high-pressure steam expands and exits the boiler via steam pipes into the steam reservoir; the steam is then controlled by a slide valve to move into a cylinder to push the piston.
[17] The motion of a body around a circular path is an example of –
A.
Uniform velocity, variable acceleration
B.
Uniform speed, uniform velocity
C.
Uniform speed, variable velocity
D.
Uniform speed, variable acceleration
Ans:
Uniform velocity, variable acceleration
Explanation :
Uniform circular motion occurs when a body moves in a circular path with constant velocity.
[18] A gas thermometer is more sensitive than a liquid thermometer because a gas:
A.
is lighter than liquid
B.
expands more than a liquid
C.
is easy to obtain
D.
does not change state easily
Ans:
does not change state easily
Explanation :
Gas is easily compressed so it would have a more versatile range of measurement at least in our atmospheric conditions. Liquid is not so easily compressed, so, very little pressure via mass w/ gravity or heat would cause it to quickly jump between changes. A gas thermometer measures temperature by the variation in volume or pressure of a gas. One common apparatus is a constant volume thermometer. Gas thermometers are often used to calibrate other thermometers.
[19] Outside of cooking utensils are generally left black from below because –
A.
it is difficult to clean daily.
B.
black surface is a good conductor of heat.
C.
black surface is a poor conductor of heat.
D.
black surface is a good absorber of heat.
Ans:
black surface is a good absorber of heat.
Explanation :
The outside surface of a utensil used for heating is coated black so that it may absorb more heat and make heating quicker. This is because black surface is a good absorber of heat.
[20] X-rays region lies between –
A.
Ultraviolet and visible region
B.
Visible and infra-red region
C.
Gamma-rays and ultraviolet region
D.
Short radio waves and long radio waves
Ans:
Gamma-rays and ultraviolet region
Explanation :
X-rays region lies between Gamma rays and ultraviolet region.
[21] A star appears twinkling in the sky because of –
A.
scattering of light by atmosphere
B.
reflection of light by atmosphere
C.
refraction of light by atmosphere
D.
diffraction of light by atmosphere
Ans:
refraction of light by atmosphere
Explanation :
A star appears twinkling in the sky because of refraction of light, by atmosphere. Light bends when it passes obliquely from one medium to another. This is called refraction of light.
[22] Water pipes in hilly areas often burst on a cold frosty night, because –
A.
The material of which pipes are made contracts due to cold and so breaks
B.
Water in the pipes freezes and on freezing water expands, so pipes break
C.
Frost makes the pipes rusty, so they break
D.
None of these
Ans:
Water in the pipes freezes and on freezing water expands, so pipes break
Explanation :
The temperature may fall below 0° C during cold frosty nights which converts the water inside the pipes into ice, resulting in an increase in volume. This exerts great force on the pipes and as a result, they burst.
[23] A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because–
A.
Stone is heavier than parachute
B.
Special mechanisms are present in parachute
C.
A parachute has a larger surface area and air resistance is more
D.
None of these
Ans:
A parachute has a larger surface area and air resistance is more
Explanation :
Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more friction slowing him down because air resistance works against the very large surface area of the parachute. A free falling skydiver that has not yet opened his parachute can make his downward speed vary between about 110 mph and 225 mph-using air resistance.
[24] In electronics what comes under tank circuit?
A.
Resistance and capacity
B.
Resistance and inductance
C.
Capacity and inductance
D.
Resistance, capacity and inductance
Ans:
Capacity and inductance
Explanation :
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C. When connected together, they can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency.
[25] In the process of magnetization of a bar –
A.
The entire bulk of the bar gets magnetized
B.
Only the surface of the bar gets magnetized
C.
Only the ends of the bar get magnetized
D.
Only some parts of the outer layers of the bar get magnetized
Ans:
The entire bulk of the bar gets magnetized
Explanation :
In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized.
Explanation :
An interesting property of matter is that its temperature remains constant during a phase change, assuming its surrounding pressure is constant. A liquid changes into gaseous state at a constant temperature called its boiling point. For example, when water is converted into vapors (gaseous state) at 100°C and so 100°C is its boiling point. The temperature remains constant at 100°C. The temperature of water increases only after all the water is evaporated. Likewise, once the temperature of a liquid is lowered to its freezing point, the temperature does not decrease until all the liquid has changed its phase to become a solid.
[4] Transformer is a device to convert –
A.
D.C. to A.C.
B.
Low voltage D.C. into high voltage D.C.
C.
Low voltage A.C. into high voltage A.C.
D.
Mechanical energy into Electrical energy
Ans:
Low voltage A.C. into high voltage A.C.
Explanation :
A transformer is an electrical device that transfers energy from one circuit to another by magnetic coupling with no moving parts. It converts high volt-age AC into low voltage AC and vice-versa.
[5] Two stones of unequal masses are thrown vertically up with the same velocity. Which of the following will happen?
A.
The heavier mass will reach greater height
B.
The lighter mass will reach greater height
C.
Both will reach the same height
D.
Any of them may reach greater height
Ans:
Both will reach the same height
Explanation :
Galileo's experiment showed that if two bodies of unequal masses are dropped from the same height, the time required by them to reach the ground are equal. If they are thrown vertically upwards with the same initial velocity, then the ratio of the time required to reach the ground is equal to unity. This means that both of them will reach the same height.
[6] Why does ice covered in sawdust ct melt quickly?
A.
Sawdust does not allow the air to touch the ice
B.
The water is absorbed by sawdust
C.
Sawdust is a bad conductor of heat
D.
Sawdust is good conductor of heat
Ans:
Sawdust is a bad conductor of heat
Explanation :
Ice needs to absorb heat energy to melt and become water (called latent heat of fusion). Since saw-dust is a poor conductor of heat, it takes more time for the ice to absorb the required heat energy. This allows ice to remain in solid state for more time when packed in saw dust.
[7] A man standing close to the platform at a railway station experiences a pulling force towards a fast moving train because of _.
A.
gravitational force between train and man.
B.
illusion of the man
C.
the centripetal force
D.
pressure difference due to fast moving air in between
Ans:
pressure difference due to fast moving air in between
Explanation :
When a fast-moving train passes a man standing on the platform at rest, the air between train and person also moves with greater speed. This rapidly moving air, by Bernoulli's principle will have a lower pressure than the still air a few feet away. The still air, having higher pressure, and being behind the man standing close will tend to push him toward the train.
[8] We feel cool when we sit near the fan, this is because –
A.
fan gives cool air.
B.
an cools surrounding air.
C.
air vapourises the sweat on our body.
D.
we feel cool when air touches the body.
Ans:
air vapourises the sweat on our body.
Explanation :
We feel comfortable sitting under a fan when we are perspiring because a fan increases the rate of evaporation of sweat (or moisture) from our body and makes us feel cool and comfortable.
[9] The average kinetic energy of the molecules of an ideal gas is directly proportional to –
A.
Velocity of Molecules
B.
Mass of Molecules
C.
Absolute temperature of the gas
D.
Temperature of environment
Ans:
Absolute temperature of the gas
Explanation :
The average kinetic energy of gas molecules is directly proportional to absolute temperature only. This implies that all molecular motion ceases if the temperature is reduced to absolute zero.
[10] When heated from 0°C to 100°C volume of a given mass of water will –
A.
Increase gradually
B.
Decrease gradually
C.
Increase and then will decrease
D.
Decrease and then will Increase
Ans:
Decrease and then will Increase
Explanation :
When heated from 00 to 100 C volume of a given mass of water will first decrease and then increase. If the word "ice" or "solid" is not mentioned, the word "water" means liquid water.
[11] Clothes keep us warm in winter because they :
A.
supply heat
B.
do not radiate heat
C.
prevent air from contacting the body
D.
prevent the heat of the body from escaping
Ans:
prevent the heat of the body from escaping
Explanation :
It is just because woolen clothes have fibres and between those fibres air is trapped which reduces heat loss. Air reduces heat loss because it is an insulator or poor conductor of heat. Hence, all the heat from our body gets trapped inside the clothes which makes us feels warmer with the clothes.
[12] In a refrigerator what produces the cooling?
A.
The ice which deposits on the freezer
B.
The sudden expansion of a compressed gas
C.
The evaporation of a volatile liquid
D.
None of these
Ans:
None of these
Explanation :
Basically, refrigeration system consists of devices that compress and expand refrigerant gas. When refrigerant gas is compressed it expels heat and when it is suddenly expanded, absorbs heat. A refrigerator (colloquially fridge) is a common household appliance that consists of a thermally insulated compartment and a heat pump (mechanical, electronic, or chemical) that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room.
[13] Microphone is a device which transforms the –
A.
sound signal into current signal
B.
current signal into sound signal
C.
sound signal into light signal
D.
light signal into sound signal
Ans:
sound signal into current signal
Explanation :
Microphone is a device which transforms the sound signal into current signal.
[14] Pressure Cooker cooks faster because –
A.
boiling point decreases with rise of pressure
B.
it cooks the food at low pressure
C.
higher temperature is attained for cooking
D.
the material of the cooker is a good conductor
Ans:
higher temperature is attained for cooking
Explanation :
In pressure cooker boiling point of water increases due to high pressure.
[15] What is a compound microscope?
A.
A microscope that has one lens.
B.
A microscope that has two sets of lenses : an occular lens and an eyepiece.
C.
A microscope whose lenses are concave.
D.
A microscope whose lenses are convex.
Ans:
A microscope that has two sets of lenses : an occular lens and an eyepiece.
Explanation :
A compound microscope is a microscope which uses multiple lenses to collect light from the sample and then a separate set of lenses to focus the light into the eye or camera. The objective lens provides the primary magnification which is compounded (multiplied) by the ocular lens (eyepiece).
[16] The temperature of boiling water in a steam engine may be high because -
A.
there are dissolved substances in water
B.
there is low pressure inside the boiler
C.
there is high pressure inside the boiler
D.
the lire is at very high temperature
Ans:
there is high pressure inside the boiler
Explanation :
In the boiler of a steam engine, there is a firebox where coal is shoveled into. The coal is kept burning at a very high temperature, and is used to heat the boiler to boil water producing a high pressure steam. The high-pressure steam expands and exits the boiler via steam pipes into the steam reservoir; the steam is then controlled by a slide valve to move into a cylinder to push the piston.
[17] The motion of a body around a circular path is an example of –
A.
Uniform velocity, variable acceleration
B.
Uniform speed, uniform velocity
C.
Uniform speed, variable velocity
D.
Uniform speed, variable acceleration
Ans:
Uniform velocity, variable acceleration
Explanation :
Uniform circular motion occurs when a body moves in a circular path with constant velocity.
[18] A gas thermometer is more sensitive than a liquid thermometer because a gas:
A.
is lighter than liquid
B.
expands more than a liquid
C.
is easy to obtain
D.
does not change state easily
Ans:
does not change state easily
Explanation :
Gas is easily compressed so it would have a more versatile range of measurement at least in our atmospheric conditions. Liquid is not so easily compressed, so, very little pressure via mass w/ gravity or heat would cause it to quickly jump between changes. A gas thermometer measures temperature by the variation in volume or pressure of a gas. One common apparatus is a constant volume thermometer. Gas thermometers are often used to calibrate other thermometers.
[19] Outside of cooking utensils are generally left black from below because –
A.
it is difficult to clean daily.
B.
black surface is a good conductor of heat.
C.
black surface is a poor conductor of heat.
D.
black surface is a good absorber of heat.
Ans:
black surface is a good absorber of heat.
Explanation :
The outside surface of a utensil used for heating is coated black so that it may absorb more heat and make heating quicker. This is because black surface is a good absorber of heat.
[20] X-rays region lies between –
A.
Ultraviolet and visible region
B.
Visible and infra-red region
C.
Gamma-rays and ultraviolet region
D.
Short radio waves and long radio waves
Ans:
Gamma-rays and ultraviolet region
Explanation :
X-rays region lies between Gamma rays and ultraviolet region.
[21] A star appears twinkling in the sky because of –
A.
scattering of light by atmosphere
B.
reflection of light by atmosphere
C.
refraction of light by atmosphere
D.
diffraction of light by atmosphere
Ans:
refraction of light by atmosphere
Explanation :
A star appears twinkling in the sky because of refraction of light, by atmosphere. Light bends when it passes obliquely from one medium to another. This is called refraction of light.
[22] Water pipes in hilly areas often burst on a cold frosty night, because –
A.
The material of which pipes are made contracts due to cold and so breaks
B.
Water in the pipes freezes and on freezing water expands, so pipes break
C.
Frost makes the pipes rusty, so they break
D.
None of these
Ans:
Water in the pipes freezes and on freezing water expands, so pipes break
Explanation :
The temperature may fall below 0° C during cold frosty nights which converts the water inside the pipes into ice, resulting in an increase in volume. This exerts great force on the pipes and as a result, they burst.
[23] A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because–
A.
Stone is heavier than parachute
B.
Special mechanisms are present in parachute
C.
A parachute has a larger surface area and air resistance is more
D.
None of these
Ans:
A parachute has a larger surface area and air resistance is more
Explanation :
Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more friction slowing him down because air resistance works against the very large surface area of the parachute. A free falling skydiver that has not yet opened his parachute can make his downward speed vary between about 110 mph and 225 mph-using air resistance.
[24] In electronics what comes under tank circuit?
A.
Resistance and capacity
B.
Resistance and inductance
C.
Capacity and inductance
D.
Resistance, capacity and inductance
Ans:
Capacity and inductance
Explanation :
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C. When connected together, they can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency.
[25] In the process of magnetization of a bar –
A.
The entire bulk of the bar gets magnetized
B.
Only the surface of the bar gets magnetized
C.
Only the ends of the bar get magnetized
D.
Only some parts of the outer layers of the bar get magnetized
Ans:
The entire bulk of the bar gets magnetized
Explanation :
In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized.
Explanation :
Galileo's experiment showed that if two bodies of unequal masses are dropped from the same height, the time required by them to reach the ground are equal. If they are thrown vertically upwards with the same initial velocity, then the ratio of the time required to reach the ground is equal to unity. This means that both of them will reach the same height.
[6] Why does ice covered in sawdust ct melt quickly?
A.
Sawdust does not allow the air to touch the ice
B.
The water is absorbed by sawdust
C.
Sawdust is a bad conductor of heat
D.
Sawdust is good conductor of heat
Ans:
Sawdust is a bad conductor of heat
Explanation :
Ice needs to absorb heat energy to melt and become water (called latent heat of fusion). Since saw-dust is a poor conductor of heat, it takes more time for the ice to absorb the required heat energy. This allows ice to remain in solid state for more time when packed in saw dust.
[7] A man standing close to the platform at a railway station experiences a pulling force towards a fast moving train because of _.
A.
gravitational force between train and man.
B.
illusion of the man
C.
the centripetal force
D.
pressure difference due to fast moving air in between
Ans:
pressure difference due to fast moving air in between
Explanation :
When a fast-moving train passes a man standing on the platform at rest, the air between train and person also moves with greater speed. This rapidly moving air, by Bernoulli's principle will have a lower pressure than the still air a few feet away. The still air, having higher pressure, and being behind the man standing close will tend to push him toward the train.
[8] We feel cool when we sit near the fan, this is because –
A.
fan gives cool air.
B.
an cools surrounding air.
C.
air vapourises the sweat on our body.
D.
we feel cool when air touches the body.
Ans:
air vapourises the sweat on our body.
Explanation :
We feel comfortable sitting under a fan when we are perspiring because a fan increases the rate of evaporation of sweat (or moisture) from our body and makes us feel cool and comfortable.
[9] The average kinetic energy of the molecules of an ideal gas is directly proportional to –
A.
Velocity of Molecules
B.
Mass of Molecules
C.
Absolute temperature of the gas
D.
Temperature of environment
Ans:
Absolute temperature of the gas
Explanation :
The average kinetic energy of gas molecules is directly proportional to absolute temperature only. This implies that all molecular motion ceases if the temperature is reduced to absolute zero.
[10] When heated from 0°C to 100°C volume of a given mass of water will –
A.
Increase gradually
B.
Decrease gradually
C.
Increase and then will decrease
D.
Decrease and then will Increase
Ans:
Decrease and then will Increase
Explanation :
When heated from 00 to 100 C volume of a given mass of water will first decrease and then increase. If the word "ice" or "solid" is not mentioned, the word "water" means liquid water.
[11] Clothes keep us warm in winter because they :
A.
supply heat
B.
do not radiate heat
C.
prevent air from contacting the body
D.
prevent the heat of the body from escaping
Ans:
prevent the heat of the body from escaping
Explanation :
It is just because woolen clothes have fibres and between those fibres air is trapped which reduces heat loss. Air reduces heat loss because it is an insulator or poor conductor of heat. Hence, all the heat from our body gets trapped inside the clothes which makes us feels warmer with the clothes.
[12] In a refrigerator what produces the cooling?
A.
The ice which deposits on the freezer
B.
The sudden expansion of a compressed gas
C.
The evaporation of a volatile liquid
D.
None of these
Ans:
None of these
Explanation :
Basically, refrigeration system consists of devices that compress and expand refrigerant gas. When refrigerant gas is compressed it expels heat and when it is suddenly expanded, absorbs heat. A refrigerator (colloquially fridge) is a common household appliance that consists of a thermally insulated compartment and a heat pump (mechanical, electronic, or chemical) that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room.
[13] Microphone is a device which transforms the –
A.
sound signal into current signal
B.
current signal into sound signal
C.
sound signal into light signal
D.
light signal into sound signal
Ans:
sound signal into current signal
Explanation :
Microphone is a device which transforms the sound signal into current signal.
[14] Pressure Cooker cooks faster because –
A.
boiling point decreases with rise of pressure
B.
it cooks the food at low pressure
C.
higher temperature is attained for cooking
D.
the material of the cooker is a good conductor
Ans:
higher temperature is attained for cooking
Explanation :
In pressure cooker boiling point of water increases due to high pressure.
[15] What is a compound microscope?
A.
A microscope that has one lens.
B.
A microscope that has two sets of lenses : an occular lens and an eyepiece.
C.
A microscope whose lenses are concave.
D.
A microscope whose lenses are convex.
Ans:
A microscope that has two sets of lenses : an occular lens and an eyepiece.
Explanation :
A compound microscope is a microscope which uses multiple lenses to collect light from the sample and then a separate set of lenses to focus the light into the eye or camera. The objective lens provides the primary magnification which is compounded (multiplied) by the ocular lens (eyepiece).
[16] The temperature of boiling water in a steam engine may be high because -
A.
there are dissolved substances in water
B.
there is low pressure inside the boiler
C.
there is high pressure inside the boiler
D.
the lire is at very high temperature
Ans:
there is high pressure inside the boiler
Explanation :
In the boiler of a steam engine, there is a firebox where coal is shoveled into. The coal is kept burning at a very high temperature, and is used to heat the boiler to boil water producing a high pressure steam. The high-pressure steam expands and exits the boiler via steam pipes into the steam reservoir; the steam is then controlled by a slide valve to move into a cylinder to push the piston.
[17] The motion of a body around a circular path is an example of –
A.
Uniform velocity, variable acceleration
B.
Uniform speed, uniform velocity
C.
Uniform speed, variable velocity
D.
Uniform speed, variable acceleration
Ans:
Uniform velocity, variable acceleration
Explanation :
Uniform circular motion occurs when a body moves in a circular path with constant velocity.
[18] A gas thermometer is more sensitive than a liquid thermometer because a gas:
A.
is lighter than liquid
B.
expands more than a liquid
C.
is easy to obtain
D.
does not change state easily
Ans:
does not change state easily
Explanation :
Gas is easily compressed so it would have a more versatile range of measurement at least in our atmospheric conditions. Liquid is not so easily compressed, so, very little pressure via mass w/ gravity or heat would cause it to quickly jump between changes. A gas thermometer measures temperature by the variation in volume or pressure of a gas. One common apparatus is a constant volume thermometer. Gas thermometers are often used to calibrate other thermometers.
[19] Outside of cooking utensils are generally left black from below because –
A.
it is difficult to clean daily.
B.
black surface is a good conductor of heat.
C.
black surface is a poor conductor of heat.
D.
black surface is a good absorber of heat.
Ans:
black surface is a good absorber of heat.
Explanation :
The outside surface of a utensil used for heating is coated black so that it may absorb more heat and make heating quicker. This is because black surface is a good absorber of heat.
[20] X-rays region lies between –
A.
Ultraviolet and visible region
B.
Visible and infra-red region
C.
Gamma-rays and ultraviolet region
D.
Short radio waves and long radio waves
Ans:
Gamma-rays and ultraviolet region
Explanation :
X-rays region lies between Gamma rays and ultraviolet region.
[21] A star appears twinkling in the sky because of –
A.
scattering of light by atmosphere
B.
reflection of light by atmosphere
C.
refraction of light by atmosphere
D.
diffraction of light by atmosphere
Ans:
refraction of light by atmosphere
Explanation :
A star appears twinkling in the sky because of refraction of light, by atmosphere. Light bends when it passes obliquely from one medium to another. This is called refraction of light.
[22] Water pipes in hilly areas often burst on a cold frosty night, because –
A.
The material of which pipes are made contracts due to cold and so breaks
B.
Water in the pipes freezes and on freezing water expands, so pipes break
C.
Frost makes the pipes rusty, so they break
D.
None of these
Ans:
Water in the pipes freezes and on freezing water expands, so pipes break
Explanation :
The temperature may fall below 0° C during cold frosty nights which converts the water inside the pipes into ice, resulting in an increase in volume. This exerts great force on the pipes and as a result, they burst.
[23] A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because–
A.
Stone is heavier than parachute
B.
Special mechanisms are present in parachute
C.
A parachute has a larger surface area and air resistance is more
D.
None of these
Ans:
A parachute has a larger surface area and air resistance is more
Explanation :
Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more friction slowing him down because air resistance works against the very large surface area of the parachute. A free falling skydiver that has not yet opened his parachute can make his downward speed vary between about 110 mph and 225 mph-using air resistance.
[24] In electronics what comes under tank circuit?
A.
Resistance and capacity
B.
Resistance and inductance
C.
Capacity and inductance
D.
Resistance, capacity and inductance
Ans:
Capacity and inductance
Explanation :
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C. When connected together, they can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency.
[25] In the process of magnetization of a bar –
A.
The entire bulk of the bar gets magnetized
B.
Only the surface of the bar gets magnetized
C.
Only the ends of the bar get magnetized
D.
Only some parts of the outer layers of the bar get magnetized
Ans:
The entire bulk of the bar gets magnetized
Explanation :
In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized.
Explanation :
When a fast-moving train passes a man standing on the platform at rest, the air between train and person also moves with greater speed. This rapidly moving air, by Bernoulli's principle will have a lower pressure than the still air a few feet away. The still air, having higher pressure, and being behind the man standing close will tend to push him toward the train.
[8] We feel cool when we sit near the fan, this is because –
A.
fan gives cool air.
B.
an cools surrounding air.
C.
air vapourises the sweat on our body.
D.
we feel cool when air touches the body.
Ans:
air vapourises the sweat on our body.
Explanation :
We feel comfortable sitting under a fan when we are perspiring because a fan increases the rate of evaporation of sweat (or moisture) from our body and makes us feel cool and comfortable.
[9] The average kinetic energy of the molecules of an ideal gas is directly proportional to –
A.
Velocity of Molecules
B.
Mass of Molecules
C.
Absolute temperature of the gas
D.
Temperature of environment
Ans:
Absolute temperature of the gas
Explanation :
The average kinetic energy of gas molecules is directly proportional to absolute temperature only. This implies that all molecular motion ceases if the temperature is reduced to absolute zero.
[10] When heated from 0°C to 100°C volume of a given mass of water will –
A.
Increase gradually
B.
Decrease gradually
C.
Increase and then will decrease
D.
Decrease and then will Increase
Ans:
Decrease and then will Increase
Explanation :
When heated from 00 to 100 C volume of a given mass of water will first decrease and then increase. If the word "ice" or "solid" is not mentioned, the word "water" means liquid water.
[11] Clothes keep us warm in winter because they :
A.
supply heat
B.
do not radiate heat
C.
prevent air from contacting the body
D.
prevent the heat of the body from escaping
Ans:
prevent the heat of the body from escaping
Explanation :
It is just because woolen clothes have fibres and between those fibres air is trapped which reduces heat loss. Air reduces heat loss because it is an insulator or poor conductor of heat. Hence, all the heat from our body gets trapped inside the clothes which makes us feels warmer with the clothes.
[12] In a refrigerator what produces the cooling?
A.
The ice which deposits on the freezer
B.
The sudden expansion of a compressed gas
C.
The evaporation of a volatile liquid
D.
None of these
Ans:
None of these
Explanation :
Basically, refrigeration system consists of devices that compress and expand refrigerant gas. When refrigerant gas is compressed it expels heat and when it is suddenly expanded, absorbs heat. A refrigerator (colloquially fridge) is a common household appliance that consists of a thermally insulated compartment and a heat pump (mechanical, electronic, or chemical) that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room.
[13] Microphone is a device which transforms the –
A.
sound signal into current signal
B.
current signal into sound signal
C.
sound signal into light signal
D.
light signal into sound signal
Ans:
sound signal into current signal
Explanation :
Microphone is a device which transforms the sound signal into current signal.
[14] Pressure Cooker cooks faster because –
A.
boiling point decreases with rise of pressure
B.
it cooks the food at low pressure
C.
higher temperature is attained for cooking
D.
the material of the cooker is a good conductor
Ans:
higher temperature is attained for cooking
Explanation :
In pressure cooker boiling point of water increases due to high pressure.
[15] What is a compound microscope?
A.
A microscope that has one lens.
B.
A microscope that has two sets of lenses : an occular lens and an eyepiece.
C.
A microscope whose lenses are concave.
D.
A microscope whose lenses are convex.
Ans:
A microscope that has two sets of lenses : an occular lens and an eyepiece.
Explanation :
A compound microscope is a microscope which uses multiple lenses to collect light from the sample and then a separate set of lenses to focus the light into the eye or camera. The objective lens provides the primary magnification which is compounded (multiplied) by the ocular lens (eyepiece).
[16] The temperature of boiling water in a steam engine may be high because -
A.
there are dissolved substances in water
B.
there is low pressure inside the boiler
C.
there is high pressure inside the boiler
D.
the lire is at very high temperature
Ans:
there is high pressure inside the boiler
Explanation :
In the boiler of a steam engine, there is a firebox where coal is shoveled into. The coal is kept burning at a very high temperature, and is used to heat the boiler to boil water producing a high pressure steam. The high-pressure steam expands and exits the boiler via steam pipes into the steam reservoir; the steam is then controlled by a slide valve to move into a cylinder to push the piston.
[17] The motion of a body around a circular path is an example of –
A.
Uniform velocity, variable acceleration
B.
Uniform speed, uniform velocity
C.
Uniform speed, variable velocity
D.
Uniform speed, variable acceleration
Ans:
Uniform velocity, variable acceleration
Explanation :
Uniform circular motion occurs when a body moves in a circular path with constant velocity.
[18] A gas thermometer is more sensitive than a liquid thermometer because a gas:
A.
is lighter than liquid
B.
expands more than a liquid
C.
is easy to obtain
D.
does not change state easily
Ans:
does not change state easily
Explanation :
Gas is easily compressed so it would have a more versatile range of measurement at least in our atmospheric conditions. Liquid is not so easily compressed, so, very little pressure via mass w/ gravity or heat would cause it to quickly jump between changes. A gas thermometer measures temperature by the variation in volume or pressure of a gas. One common apparatus is a constant volume thermometer. Gas thermometers are often used to calibrate other thermometers.
[19] Outside of cooking utensils are generally left black from below because –
A.
it is difficult to clean daily.
B.
black surface is a good conductor of heat.
C.
black surface is a poor conductor of heat.
D.
black surface is a good absorber of heat.
Ans:
black surface is a good absorber of heat.
Explanation :
The outside surface of a utensil used for heating is coated black so that it may absorb more heat and make heating quicker. This is because black surface is a good absorber of heat.
[20] X-rays region lies between –
A.
Ultraviolet and visible region
B.
Visible and infra-red region
C.
Gamma-rays and ultraviolet region
D.
Short radio waves and long radio waves
Ans:
Gamma-rays and ultraviolet region
Explanation :
X-rays region lies between Gamma rays and ultraviolet region.
[21] A star appears twinkling in the sky because of –
A.
scattering of light by atmosphere
B.
reflection of light by atmosphere
C.
refraction of light by atmosphere
D.
diffraction of light by atmosphere
Ans:
refraction of light by atmosphere
Explanation :
A star appears twinkling in the sky because of refraction of light, by atmosphere. Light bends when it passes obliquely from one medium to another. This is called refraction of light.
[22] Water pipes in hilly areas often burst on a cold frosty night, because –
A.
The material of which pipes are made contracts due to cold and so breaks
B.
Water in the pipes freezes and on freezing water expands, so pipes break
C.
Frost makes the pipes rusty, so they break
D.
None of these
Ans:
Water in the pipes freezes and on freezing water expands, so pipes break
Explanation :
The temperature may fall below 0° C during cold frosty nights which converts the water inside the pipes into ice, resulting in an increase in volume. This exerts great force on the pipes and as a result, they burst.
[23] A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because–
A.
Stone is heavier than parachute
B.
Special mechanisms are present in parachute
C.
A parachute has a larger surface area and air resistance is more
D.
None of these
Ans:
A parachute has a larger surface area and air resistance is more
Explanation :
Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more friction slowing him down because air resistance works against the very large surface area of the parachute. A free falling skydiver that has not yet opened his parachute can make his downward speed vary between about 110 mph and 225 mph-using air resistance.
[24] In electronics what comes under tank circuit?
A.
Resistance and capacity
B.
Resistance and inductance
C.
Capacity and inductance
D.
Resistance, capacity and inductance
Ans:
Capacity and inductance
Explanation :
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C. When connected together, they can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency.
[25] In the process of magnetization of a bar –
A.
The entire bulk of the bar gets magnetized
B.
Only the surface of the bar gets magnetized
C.
Only the ends of the bar get magnetized
D.
Only some parts of the outer layers of the bar get magnetized
Ans:
The entire bulk of the bar gets magnetized
Explanation :
In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized.
Explanation :
The average kinetic energy of gas molecules is directly proportional to absolute temperature only. This implies that all molecular motion ceases if the temperature is reduced to absolute zero.
[10] When heated from 0°C to 100°C volume of a given mass of water will –
A.
Increase gradually
B.
Decrease gradually
C.
Increase and then will decrease
D.
Decrease and then will Increase
Ans:
Decrease and then will Increase
Explanation :
When heated from 00 to 100 C volume of a given mass of water will first decrease and then increase. If the word "ice" or "solid" is not mentioned, the word "water" means liquid water.
[11] Clothes keep us warm in winter because they :
A.
supply heat
B.
do not radiate heat
C.
prevent air from contacting the body
D.
prevent the heat of the body from escaping
Ans:
prevent the heat of the body from escaping
Explanation :
It is just because woolen clothes have fibres and between those fibres air is trapped which reduces heat loss. Air reduces heat loss because it is an insulator or poor conductor of heat. Hence, all the heat from our body gets trapped inside the clothes which makes us feels warmer with the clothes.
[12] In a refrigerator what produces the cooling?
A.
The ice which deposits on the freezer
B.
The sudden expansion of a compressed gas
C.
The evaporation of a volatile liquid
D.
None of these
Ans:
None of these
Explanation :
Basically, refrigeration system consists of devices that compress and expand refrigerant gas. When refrigerant gas is compressed it expels heat and when it is suddenly expanded, absorbs heat. A refrigerator (colloquially fridge) is a common household appliance that consists of a thermally insulated compartment and a heat pump (mechanical, electronic, or chemical) that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room.
[13] Microphone is a device which transforms the –
A.
sound signal into current signal
B.
current signal into sound signal
C.
sound signal into light signal
D.
light signal into sound signal
Ans:
sound signal into current signal
Explanation :
Microphone is a device which transforms the sound signal into current signal.
[14] Pressure Cooker cooks faster because –
A.
boiling point decreases with rise of pressure
B.
it cooks the food at low pressure
C.
higher temperature is attained for cooking
D.
the material of the cooker is a good conductor
Ans:
higher temperature is attained for cooking
Explanation :
In pressure cooker boiling point of water increases due to high pressure.
[15] What is a compound microscope?
A.
A microscope that has one lens.
B.
A microscope that has two sets of lenses : an occular lens and an eyepiece.
C.
A microscope whose lenses are concave.
D.
A microscope whose lenses are convex.
Ans:
A microscope that has two sets of lenses : an occular lens and an eyepiece.
Explanation :
A compound microscope is a microscope which uses multiple lenses to collect light from the sample and then a separate set of lenses to focus the light into the eye or camera. The objective lens provides the primary magnification which is compounded (multiplied) by the ocular lens (eyepiece).
[16] The temperature of boiling water in a steam engine may be high because -
A.
there are dissolved substances in water
B.
there is low pressure inside the boiler
C.
there is high pressure inside the boiler
D.
the lire is at very high temperature
Ans:
there is high pressure inside the boiler
Explanation :
In the boiler of a steam engine, there is a firebox where coal is shoveled into. The coal is kept burning at a very high temperature, and is used to heat the boiler to boil water producing a high pressure steam. The high-pressure steam expands and exits the boiler via steam pipes into the steam reservoir; the steam is then controlled by a slide valve to move into a cylinder to push the piston.
[17] The motion of a body around a circular path is an example of –
A.
Uniform velocity, variable acceleration
B.
Uniform speed, uniform velocity
C.
Uniform speed, variable velocity
D.
Uniform speed, variable acceleration
Ans:
Uniform velocity, variable acceleration
Explanation :
Uniform circular motion occurs when a body moves in a circular path with constant velocity.
[18] A gas thermometer is more sensitive than a liquid thermometer because a gas:
A.
is lighter than liquid
B.
expands more than a liquid
C.
is easy to obtain
D.
does not change state easily
Ans:
does not change state easily
Explanation :
Gas is easily compressed so it would have a more versatile range of measurement at least in our atmospheric conditions. Liquid is not so easily compressed, so, very little pressure via mass w/ gravity or heat would cause it to quickly jump between changes. A gas thermometer measures temperature by the variation in volume or pressure of a gas. One common apparatus is a constant volume thermometer. Gas thermometers are often used to calibrate other thermometers.
[19] Outside of cooking utensils are generally left black from below because –
A.
it is difficult to clean daily.
B.
black surface is a good conductor of heat.
C.
black surface is a poor conductor of heat.
D.
black surface is a good absorber of heat.
Ans:
black surface is a good absorber of heat.
Explanation :
The outside surface of a utensil used for heating is coated black so that it may absorb more heat and make heating quicker. This is because black surface is a good absorber of heat.
[20] X-rays region lies between –
A.
Ultraviolet and visible region
B.
Visible and infra-red region
C.
Gamma-rays and ultraviolet region
D.
Short radio waves and long radio waves
Ans:
Gamma-rays and ultraviolet region
Explanation :
X-rays region lies between Gamma rays and ultraviolet region.
[21] A star appears twinkling in the sky because of –
A.
scattering of light by atmosphere
B.
reflection of light by atmosphere
C.
refraction of light by atmosphere
D.
diffraction of light by atmosphere
Ans:
refraction of light by atmosphere
Explanation :
A star appears twinkling in the sky because of refraction of light, by atmosphere. Light bends when it passes obliquely from one medium to another. This is called refraction of light.
[22] Water pipes in hilly areas often burst on a cold frosty night, because –
A.
The material of which pipes are made contracts due to cold and so breaks
B.
Water in the pipes freezes and on freezing water expands, so pipes break
C.
Frost makes the pipes rusty, so they break
D.
None of these
Ans:
Water in the pipes freezes and on freezing water expands, so pipes break
Explanation :
The temperature may fall below 0° C during cold frosty nights which converts the water inside the pipes into ice, resulting in an increase in volume. This exerts great force on the pipes and as a result, they burst.
[23] A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because–
A.
Stone is heavier than parachute
B.
Special mechanisms are present in parachute
C.
A parachute has a larger surface area and air resistance is more
D.
None of these
Ans:
A parachute has a larger surface area and air resistance is more
Explanation :
Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more friction slowing him down because air resistance works against the very large surface area of the parachute. A free falling skydiver that has not yet opened his parachute can make his downward speed vary between about 110 mph and 225 mph-using air resistance.
[24] In electronics what comes under tank circuit?
A.
Resistance and capacity
B.
Resistance and inductance
C.
Capacity and inductance
D.
Resistance, capacity and inductance
Ans:
Capacity and inductance
Explanation :
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C. When connected together, they can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency.
[25] In the process of magnetization of a bar –
A.
The entire bulk of the bar gets magnetized
B.
Only the surface of the bar gets magnetized
C.
Only the ends of the bar get magnetized
D.
Only some parts of the outer layers of the bar get magnetized
Ans:
The entire bulk of the bar gets magnetized
Explanation :
In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized.
Explanation :
It is just because woolen clothes have fibres and between those fibres air is trapped which reduces heat loss. Air reduces heat loss because it is an insulator or poor conductor of heat. Hence, all the heat from our body gets trapped inside the clothes which makes us feels warmer with the clothes.
[12] In a refrigerator what produces the cooling?
A.
The ice which deposits on the freezer
B.
The sudden expansion of a compressed gas
C.
The evaporation of a volatile liquid
D.
None of these
Ans:
None of these
Explanation :
Basically, refrigeration system consists of devices that compress and expand refrigerant gas. When refrigerant gas is compressed it expels heat and when it is suddenly expanded, absorbs heat. A refrigerator (colloquially fridge) is a common household appliance that consists of a thermally insulated compartment and a heat pump (mechanical, electronic, or chemical) that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room.
[13] Microphone is a device which transforms the –
A.
sound signal into current signal
B.
current signal into sound signal
C.
sound signal into light signal
D.
light signal into sound signal
Ans:
sound signal into current signal
Explanation :
Microphone is a device which transforms the sound signal into current signal.
[14] Pressure Cooker cooks faster because –
A.
boiling point decreases with rise of pressure
B.
it cooks the food at low pressure
C.
higher temperature is attained for cooking
D.
the material of the cooker is a good conductor
Ans:
higher temperature is attained for cooking
Explanation :
In pressure cooker boiling point of water increases due to high pressure.
[15] What is a compound microscope?
A.
A microscope that has one lens.
B.
A microscope that has two sets of lenses : an occular lens and an eyepiece.
C.
A microscope whose lenses are concave.
D.
A microscope whose lenses are convex.
Ans:
A microscope that has two sets of lenses : an occular lens and an eyepiece.
Explanation :
A compound microscope is a microscope which uses multiple lenses to collect light from the sample and then a separate set of lenses to focus the light into the eye or camera. The objective lens provides the primary magnification which is compounded (multiplied) by the ocular lens (eyepiece).
[16] The temperature of boiling water in a steam engine may be high because -
A.
there are dissolved substances in water
B.
there is low pressure inside the boiler
C.
there is high pressure inside the boiler
D.
the lire is at very high temperature
Ans:
there is high pressure inside the boiler
Explanation :
In the boiler of a steam engine, there is a firebox where coal is shoveled into. The coal is kept burning at a very high temperature, and is used to heat the boiler to boil water producing a high pressure steam. The high-pressure steam expands and exits the boiler via steam pipes into the steam reservoir; the steam is then controlled by a slide valve to move into a cylinder to push the piston.
[17] The motion of a body around a circular path is an example of –
A.
Uniform velocity, variable acceleration
B.
Uniform speed, uniform velocity
C.
Uniform speed, variable velocity
D.
Uniform speed, variable acceleration
Ans:
Uniform velocity, variable acceleration
Explanation :
Uniform circular motion occurs when a body moves in a circular path with constant velocity.
[18] A gas thermometer is more sensitive than a liquid thermometer because a gas:
A.
is lighter than liquid
B.
expands more than a liquid
C.
is easy to obtain
D.
does not change state easily
Ans:
does not change state easily
Explanation :
Gas is easily compressed so it would have a more versatile range of measurement at least in our atmospheric conditions. Liquid is not so easily compressed, so, very little pressure via mass w/ gravity or heat would cause it to quickly jump between changes. A gas thermometer measures temperature by the variation in volume or pressure of a gas. One common apparatus is a constant volume thermometer. Gas thermometers are often used to calibrate other thermometers.
[19] Outside of cooking utensils are generally left black from below because –
A.
it is difficult to clean daily.
B.
black surface is a good conductor of heat.
C.
black surface is a poor conductor of heat.
D.
black surface is a good absorber of heat.
Ans:
black surface is a good absorber of heat.
Explanation :
The outside surface of a utensil used for heating is coated black so that it may absorb more heat and make heating quicker. This is because black surface is a good absorber of heat.
[20] X-rays region lies between –
A.
Ultraviolet and visible region
B.
Visible and infra-red region
C.
Gamma-rays and ultraviolet region
D.
Short radio waves and long radio waves
Ans:
Gamma-rays and ultraviolet region
Explanation :
X-rays region lies between Gamma rays and ultraviolet region.
[21] A star appears twinkling in the sky because of –
A.
scattering of light by atmosphere
B.
reflection of light by atmosphere
C.
refraction of light by atmosphere
D.
diffraction of light by atmosphere
Ans:
refraction of light by atmosphere
Explanation :
A star appears twinkling in the sky because of refraction of light, by atmosphere. Light bends when it passes obliquely from one medium to another. This is called refraction of light.
[22] Water pipes in hilly areas often burst on a cold frosty night, because –
A.
The material of which pipes are made contracts due to cold and so breaks
B.
Water in the pipes freezes and on freezing water expands, so pipes break
C.
Frost makes the pipes rusty, so they break
D.
None of these
Ans:
Water in the pipes freezes and on freezing water expands, so pipes break
Explanation :
The temperature may fall below 0° C during cold frosty nights which converts the water inside the pipes into ice, resulting in an increase in volume. This exerts great force on the pipes and as a result, they burst.
[23] A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because–
A.
Stone is heavier than parachute
B.
Special mechanisms are present in parachute
C.
A parachute has a larger surface area and air resistance is more
D.
None of these
Ans:
A parachute has a larger surface area and air resistance is more
Explanation :
Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more friction slowing him down because air resistance works against the very large surface area of the parachute. A free falling skydiver that has not yet opened his parachute can make his downward speed vary between about 110 mph and 225 mph-using air resistance.
[24] In electronics what comes under tank circuit?
A.
Resistance and capacity
B.
Resistance and inductance
C.
Capacity and inductance
D.
Resistance, capacity and inductance
Ans:
Capacity and inductance
Explanation :
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C. When connected together, they can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency.
[25] In the process of magnetization of a bar –
A.
The entire bulk of the bar gets magnetized
B.
Only the surface of the bar gets magnetized
C.
Only the ends of the bar get magnetized
D.
Only some parts of the outer layers of the bar get magnetized
Ans:
The entire bulk of the bar gets magnetized
Explanation :
In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized.
Explanation :
Microphone is a device which transforms the sound signal into current signal.
[14] Pressure Cooker cooks faster because –
A.
boiling point decreases with rise of pressure
B.
it cooks the food at low pressure
C.
higher temperature is attained for cooking
D.
the material of the cooker is a good conductor
Ans:
higher temperature is attained for cooking
Explanation :
In pressure cooker boiling point of water increases due to high pressure.
[15] What is a compound microscope?
A.
A microscope that has one lens.
B.
A microscope that has two sets of lenses : an occular lens and an eyepiece.
C.
A microscope whose lenses are concave.
D.
A microscope whose lenses are convex.
Ans:
A microscope that has two sets of lenses : an occular lens and an eyepiece.
Explanation :
A compound microscope is a microscope which uses multiple lenses to collect light from the sample and then a separate set of lenses to focus the light into the eye or camera. The objective lens provides the primary magnification which is compounded (multiplied) by the ocular lens (eyepiece).
[16] The temperature of boiling water in a steam engine may be high because -
A.
there are dissolved substances in water
B.
there is low pressure inside the boiler
C.
there is high pressure inside the boiler
D.
the lire is at very high temperature
Ans:
there is high pressure inside the boiler
Explanation :
In the boiler of a steam engine, there is a firebox where coal is shoveled into. The coal is kept burning at a very high temperature, and is used to heat the boiler to boil water producing a high pressure steam. The high-pressure steam expands and exits the boiler via steam pipes into the steam reservoir; the steam is then controlled by a slide valve to move into a cylinder to push the piston.
[17] The motion of a body around a circular path is an example of –
A.
Uniform velocity, variable acceleration
B.
Uniform speed, uniform velocity
C.
Uniform speed, variable velocity
D.
Uniform speed, variable acceleration
Ans:
Uniform velocity, variable acceleration
Explanation :
Uniform circular motion occurs when a body moves in a circular path with constant velocity.
[18] A gas thermometer is more sensitive than a liquid thermometer because a gas:
A.
is lighter than liquid
B.
expands more than a liquid
C.
is easy to obtain
D.
does not change state easily
Ans:
does not change state easily
Explanation :
Gas is easily compressed so it would have a more versatile range of measurement at least in our atmospheric conditions. Liquid is not so easily compressed, so, very little pressure via mass w/ gravity or heat would cause it to quickly jump between changes. A gas thermometer measures temperature by the variation in volume or pressure of a gas. One common apparatus is a constant volume thermometer. Gas thermometers are often used to calibrate other thermometers.
[19] Outside of cooking utensils are generally left black from below because –
A.
it is difficult to clean daily.
B.
black surface is a good conductor of heat.
C.
black surface is a poor conductor of heat.
D.
black surface is a good absorber of heat.
Ans:
black surface is a good absorber of heat.
Explanation :
The outside surface of a utensil used for heating is coated black so that it may absorb more heat and make heating quicker. This is because black surface is a good absorber of heat.
[20] X-rays region lies between –
A.
Ultraviolet and visible region
B.
Visible and infra-red region
C.
Gamma-rays and ultraviolet region
D.
Short radio waves and long radio waves
Ans:
Gamma-rays and ultraviolet region
Explanation :
X-rays region lies between Gamma rays and ultraviolet region.
[21] A star appears twinkling in the sky because of –
A.
scattering of light by atmosphere
B.
reflection of light by atmosphere
C.
refraction of light by atmosphere
D.
diffraction of light by atmosphere
Ans:
refraction of light by atmosphere
Explanation :
A star appears twinkling in the sky because of refraction of light, by atmosphere. Light bends when it passes obliquely from one medium to another. This is called refraction of light.
[22] Water pipes in hilly areas often burst on a cold frosty night, because –
A.
The material of which pipes are made contracts due to cold and so breaks
B.
Water in the pipes freezes and on freezing water expands, so pipes break
C.
Frost makes the pipes rusty, so they break
D.
None of these
Ans:
Water in the pipes freezes and on freezing water expands, so pipes break
Explanation :
The temperature may fall below 0° C during cold frosty nights which converts the water inside the pipes into ice, resulting in an increase in volume. This exerts great force on the pipes and as a result, they burst.
[23] A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because–
A.
Stone is heavier than parachute
B.
Special mechanisms are present in parachute
C.
A parachute has a larger surface area and air resistance is more
D.
None of these
Ans:
A parachute has a larger surface area and air resistance is more
Explanation :
Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more friction slowing him down because air resistance works against the very large surface area of the parachute. A free falling skydiver that has not yet opened his parachute can make his downward speed vary between about 110 mph and 225 mph-using air resistance.
[24] In electronics what comes under tank circuit?
A.
Resistance and capacity
B.
Resistance and inductance
C.
Capacity and inductance
D.
Resistance, capacity and inductance
Ans:
Capacity and inductance
Explanation :
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C. When connected together, they can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency.
[25] In the process of magnetization of a bar –
A.
The entire bulk of the bar gets magnetized
B.
Only the surface of the bar gets magnetized
C.
Only the ends of the bar get magnetized
D.
Only some parts of the outer layers of the bar get magnetized
Ans:
The entire bulk of the bar gets magnetized
Explanation :
In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized.
Explanation :
A compound microscope is a microscope which uses multiple lenses to collect light from the sample and then a separate set of lenses to focus the light into the eye or camera. The objective lens provides the primary magnification which is compounded (multiplied) by the ocular lens (eyepiece).
[16] The temperature of boiling water in a steam engine may be high because -
A.
there are dissolved substances in water
B.
there is low pressure inside the boiler
C.
there is high pressure inside the boiler
D.
the lire is at very high temperature
Ans:
there is high pressure inside the boiler
Explanation :
In the boiler of a steam engine, there is a firebox where coal is shoveled into. The coal is kept burning at a very high temperature, and is used to heat the boiler to boil water producing a high pressure steam. The high-pressure steam expands and exits the boiler via steam pipes into the steam reservoir; the steam is then controlled by a slide valve to move into a cylinder to push the piston.
[17] The motion of a body around a circular path is an example of –
A.
Uniform velocity, variable acceleration
B.
Uniform speed, uniform velocity
C.
Uniform speed, variable velocity
D.
Uniform speed, variable acceleration
Ans:
Uniform velocity, variable acceleration
Explanation :
Uniform circular motion occurs when a body moves in a circular path with constant velocity.
[18] A gas thermometer is more sensitive than a liquid thermometer because a gas:
A.
is lighter than liquid
B.
expands more than a liquid
C.
is easy to obtain
D.
does not change state easily
Ans:
does not change state easily
Explanation :
Gas is easily compressed so it would have a more versatile range of measurement at least in our atmospheric conditions. Liquid is not so easily compressed, so, very little pressure via mass w/ gravity or heat would cause it to quickly jump between changes. A gas thermometer measures temperature by the variation in volume or pressure of a gas. One common apparatus is a constant volume thermometer. Gas thermometers are often used to calibrate other thermometers.
[19] Outside of cooking utensils are generally left black from below because –
A.
it is difficult to clean daily.
B.
black surface is a good conductor of heat.
C.
black surface is a poor conductor of heat.
D.
black surface is a good absorber of heat.
Ans:
black surface is a good absorber of heat.
Explanation :
The outside surface of a utensil used for heating is coated black so that it may absorb more heat and make heating quicker. This is because black surface is a good absorber of heat.
[20] X-rays region lies between –
A.
Ultraviolet and visible region
B.
Visible and infra-red region
C.
Gamma-rays and ultraviolet region
D.
Short radio waves and long radio waves
Ans:
Gamma-rays and ultraviolet region
Explanation :
X-rays region lies between Gamma rays and ultraviolet region.
[21] A star appears twinkling in the sky because of –
A.
scattering of light by atmosphere
B.
reflection of light by atmosphere
C.
refraction of light by atmosphere
D.
diffraction of light by atmosphere
Ans:
refraction of light by atmosphere
Explanation :
A star appears twinkling in the sky because of refraction of light, by atmosphere. Light bends when it passes obliquely from one medium to another. This is called refraction of light.
[22] Water pipes in hilly areas often burst on a cold frosty night, because –
A.
The material of which pipes are made contracts due to cold and so breaks
B.
Water in the pipes freezes and on freezing water expands, so pipes break
C.
Frost makes the pipes rusty, so they break
D.
None of these
Ans:
Water in the pipes freezes and on freezing water expands, so pipes break
Explanation :
The temperature may fall below 0° C during cold frosty nights which converts the water inside the pipes into ice, resulting in an increase in volume. This exerts great force on the pipes and as a result, they burst.
[23] A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because–
A.
Stone is heavier than parachute
B.
Special mechanisms are present in parachute
C.
A parachute has a larger surface area and air resistance is more
D.
None of these
Ans:
A parachute has a larger surface area and air resistance is more
Explanation :
Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more friction slowing him down because air resistance works against the very large surface area of the parachute. A free falling skydiver that has not yet opened his parachute can make his downward speed vary between about 110 mph and 225 mph-using air resistance.
[24] In electronics what comes under tank circuit?
A.
Resistance and capacity
B.
Resistance and inductance
C.
Capacity and inductance
D.
Resistance, capacity and inductance
Ans:
Capacity and inductance
Explanation :
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C. When connected together, they can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency.
[25] In the process of magnetization of a bar –
A.
The entire bulk of the bar gets magnetized
B.
Only the surface of the bar gets magnetized
C.
Only the ends of the bar get magnetized
D.
Only some parts of the outer layers of the bar get magnetized
Ans:
The entire bulk of the bar gets magnetized
Explanation :
In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized.
Explanation :
Uniform circular motion occurs when a body moves in a circular path with constant velocity.
[18] A gas thermometer is more sensitive than a liquid thermometer because a gas:
A.
is lighter than liquid
B.
expands more than a liquid
C.
is easy to obtain
D.
does not change state easily
Ans:
does not change state easily
Explanation :
Gas is easily compressed so it would have a more versatile range of measurement at least in our atmospheric conditions. Liquid is not so easily compressed, so, very little pressure via mass w/ gravity or heat would cause it to quickly jump between changes. A gas thermometer measures temperature by the variation in volume or pressure of a gas. One common apparatus is a constant volume thermometer. Gas thermometers are often used to calibrate other thermometers.
[19] Outside of cooking utensils are generally left black from below because –
A.
it is difficult to clean daily.
B.
black surface is a good conductor of heat.
C.
black surface is a poor conductor of heat.
D.
black surface is a good absorber of heat.
Ans:
black surface is a good absorber of heat.
Explanation :
The outside surface of a utensil used for heating is coated black so that it may absorb more heat and make heating quicker. This is because black surface is a good absorber of heat.
[20] X-rays region lies between –
A.
Ultraviolet and visible region
B.
Visible and infra-red region
C.
Gamma-rays and ultraviolet region
D.
Short radio waves and long radio waves
Ans:
Gamma-rays and ultraviolet region
Explanation :
X-rays region lies between Gamma rays and ultraviolet region.
[21] A star appears twinkling in the sky because of –
A.
scattering of light by atmosphere
B.
reflection of light by atmosphere
C.
refraction of light by atmosphere
D.
diffraction of light by atmosphere
Ans:
refraction of light by atmosphere
Explanation :
A star appears twinkling in the sky because of refraction of light, by atmosphere. Light bends when it passes obliquely from one medium to another. This is called refraction of light.
[22] Water pipes in hilly areas often burst on a cold frosty night, because –
A.
The material of which pipes are made contracts due to cold and so breaks
B.
Water in the pipes freezes and on freezing water expands, so pipes break
C.
Frost makes the pipes rusty, so they break
D.
None of these
Ans:
Water in the pipes freezes and on freezing water expands, so pipes break
Explanation :
The temperature may fall below 0° C during cold frosty nights which converts the water inside the pipes into ice, resulting in an increase in volume. This exerts great force on the pipes and as a result, they burst.
[23] A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because–
A.
Stone is heavier than parachute
B.
Special mechanisms are present in parachute
C.
A parachute has a larger surface area and air resistance is more
D.
None of these
Ans:
A parachute has a larger surface area and air resistance is more
Explanation :
Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more friction slowing him down because air resistance works against the very large surface area of the parachute. A free falling skydiver that has not yet opened his parachute can make his downward speed vary between about 110 mph and 225 mph-using air resistance.
[24] In electronics what comes under tank circuit?
A.
Resistance and capacity
B.
Resistance and inductance
C.
Capacity and inductance
D.
Resistance, capacity and inductance
Ans:
Capacity and inductance
Explanation :
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C. When connected together, they can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency.
[25] In the process of magnetization of a bar –
A.
The entire bulk of the bar gets magnetized
B.
Only the surface of the bar gets magnetized
C.
Only the ends of the bar get magnetized
D.
Only some parts of the outer layers of the bar get magnetized
Ans:
The entire bulk of the bar gets magnetized
Explanation :
In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized.
Explanation :
The outside surface of a utensil used for heating is coated black so that it may absorb more heat and make heating quicker. This is because black surface is a good absorber of heat.
[20] X-rays region lies between –
A.
Ultraviolet and visible region
B.
Visible and infra-red region
C.
Gamma-rays and ultraviolet region
D.
Short radio waves and long radio waves
Ans:
Gamma-rays and ultraviolet region
Explanation :
X-rays region lies between Gamma rays and ultraviolet region.
[21] A star appears twinkling in the sky because of –
A.
scattering of light by atmosphere
B.
reflection of light by atmosphere
C.
refraction of light by atmosphere
D.
diffraction of light by atmosphere
Ans:
refraction of light by atmosphere
Explanation :
A star appears twinkling in the sky because of refraction of light, by atmosphere. Light bends when it passes obliquely from one medium to another. This is called refraction of light.
[22] Water pipes in hilly areas often burst on a cold frosty night, because –
A.
The material of which pipes are made contracts due to cold and so breaks
B.
Water in the pipes freezes and on freezing water expands, so pipes break
C.
Frost makes the pipes rusty, so they break
D.
None of these
Ans:
Water in the pipes freezes and on freezing water expands, so pipes break
Explanation :
The temperature may fall below 0° C during cold frosty nights which converts the water inside the pipes into ice, resulting in an increase in volume. This exerts great force on the pipes and as a result, they burst.
[23] A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because–
A.
Stone is heavier than parachute
B.
Special mechanisms are present in parachute
C.
A parachute has a larger surface area and air resistance is more
D.
None of these
Ans:
A parachute has a larger surface area and air resistance is more
Explanation :
Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more friction slowing him down because air resistance works against the very large surface area of the parachute. A free falling skydiver that has not yet opened his parachute can make his downward speed vary between about 110 mph and 225 mph-using air resistance.
[24] In electronics what comes under tank circuit?
A.
Resistance and capacity
B.
Resistance and inductance
C.
Capacity and inductance
D.
Resistance, capacity and inductance
Ans:
Capacity and inductance
Explanation :
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C. When connected together, they can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency.
[25] In the process of magnetization of a bar –
A.
The entire bulk of the bar gets magnetized
B.
Only the surface of the bar gets magnetized
C.
Only the ends of the bar get magnetized
D.
Only some parts of the outer layers of the bar get magnetized
Ans:
The entire bulk of the bar gets magnetized
Explanation :
In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized.
Explanation :
A star appears twinkling in the sky because of refraction of light, by atmosphere. Light bends when it passes obliquely from one medium to another. This is called refraction of light.
[22] Water pipes in hilly areas often burst on a cold frosty night, because –
A.
The material of which pipes are made contracts due to cold and so breaks
B.
Water in the pipes freezes and on freezing water expands, so pipes break
C.
Frost makes the pipes rusty, so they break
D.
None of these
Ans:
Water in the pipes freezes and on freezing water expands, so pipes break
Explanation :
The temperature may fall below 0° C during cold frosty nights which converts the water inside the pipes into ice, resulting in an increase in volume. This exerts great force on the pipes and as a result, they burst.
[23] A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because–
A.
Stone is heavier than parachute
B.
Special mechanisms are present in parachute
C.
A parachute has a larger surface area and air resistance is more
D.
None of these
Ans:
A parachute has a larger surface area and air resistance is more
Explanation :
Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more friction slowing him down because air resistance works against the very large surface area of the parachute. A free falling skydiver that has not yet opened his parachute can make his downward speed vary between about 110 mph and 225 mph-using air resistance.
[24] In electronics what comes under tank circuit?
A.
Resistance and capacity
B.
Resistance and inductance
C.
Capacity and inductance
D.
Resistance, capacity and inductance
Ans:
Capacity and inductance
Explanation :
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C. When connected together, they can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency.
[25] In the process of magnetization of a bar –
A.
The entire bulk of the bar gets magnetized
B.
Only the surface of the bar gets magnetized
C.
Only the ends of the bar get magnetized
D.
Only some parts of the outer layers of the bar get magnetized
Ans:
The entire bulk of the bar gets magnetized
Explanation :
In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized.
Explanation :
Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more friction slowing him down because air resistance works against the very large surface area of the parachute. A free falling skydiver that has not yet opened his parachute can make his downward speed vary between about 110 mph and 225 mph-using air resistance.
[24] In electronics what comes under tank circuit?
A.
Resistance and capacity
B.
Resistance and inductance
C.
Capacity and inductance
D.
Resistance, capacity and inductance
Ans:
Capacity and inductance
Explanation :
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C. When connected together, they can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency.
[25] In the process of magnetization of a bar –
A.
The entire bulk of the bar gets magnetized
B.
Only the surface of the bar gets magnetized
C.
Only the ends of the bar get magnetized
D.
Only some parts of the outer layers of the bar get magnetized
Ans:
The entire bulk of the bar gets magnetized
Explanation :
In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized.
Explanation :
In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized.