[1] The method of magnetization is:
A.
hammering a magnet
B.
heating a magnet
C.
passing direct current through it
D.
passing alternating current through it
Ans:
hammering a magnet
Explanation :
Hammering a rod will either allow it to become slightly magnetic inlaid along a magnetic field (i.e.North - South) or demagnetize it if laid across the field lines (i.e. East-West). A current passing through a coil will produce a magnetic field.
[2] Which among the following is false about work?
A.
If displacement is zero, work is zero
B.
Work done can be negative
C.
It is a vector quantity
D.
Its unit is Joule
Ans:
It is a vector quantity
Explanation :
Vector, in physics, a quantity that has both magnitude and direction. For example, displacement, velocity, and acceleration are vector quantities, while speed (the magnitude of velocity), time, and mass are scalars.
[3] Which of the following is false?
A.
Most carbon compounds are poor conductors of electricity.
B.
The force of attraction between carbon molecules is not very strong.
C.
The atomic number of carbon is 6.
D.
The earth’s crust has about 2% carbon in the form of minerals.
Ans:
The earth’s crust has about 2% carbon in the form of minerals.
Explanation :
0
[4] Two vectors are said to be equal if –
A.
only their magnitudes are same
B.
only their directions are same
C.
both magnitude and direction are same
D.
magnitudes are same but directions are opposite
Ans:
both magnitude and direction are same
Explanation :
If the magnitude as well as direction of two vectors are equal, then they are known as equal vectors. In other words, two vectors are said to be equal, if they possess equal magnitude and are headed towards the same direction. For two equal vectors, their directed line segments must be parallel.
[5] A real gas can act as an ideal gas in -
A.
high pressure and low temperature
B.
low pressure and high temperature
C.
high pressure and high temperature
D.
low pressure and low temperature
Ans:
low pressure and high temperature
Explanation :
Real gases approximate ideal gases when their pressure is relatively low, and their temperature reasonably high. A real gas deviates increasingly from ideality as it is compressed and cooled to near the point at which it will condense into a liquid.
[6] The Dynamo converts –
A.
Electrical Energy into Mechanical Energy
B.
Mechanical Energy into Magnetic Energy
C.
None of these
D.
Mechanical Energy into Electrical Energy
Ans:
Mechanical Energy into Electrical Energy
Explanation :
Dynamo is a device for converting mechanical energy into electrical energy, especially one that produces direct current. It uses electromagnetic principles to convert mechanical rotation into a pulsing direct electric current through the use of a commutator.
[7] Winch of the following is not true about X-rays?
A.
have low penetrating power
B.
travel with the speed of light
C.
Can be reflected or refracted
D.
can affect photographic plates
Ans:
have low penetrating power
Explanation :
X-rays and gamma rays are photons, i.e. high-energy light-waves. When emitted by a source, for example, radium or cobalt, located outside the body, they easily pass through the body, hence they are usually called penetrating radiation. Because X-rays are penetrating, they can be used in diagnostic medicine to image human bones or human organs made opaque by a dye.
[8] A Fuse wire is characterized by –
A.
High resistance and low melting point
B.
High resistance and high melting point
C.
Low resistance and high melting point
D.
Low resistance and low melting point
Ans:
Low resistance and low melting point
Explanation :
A fuse is a type of low resistance resistor that acts as a sacrificial device to provide over current protection, of either the load or source circuit. Low resistance causes the fuse wire to melt if a current more than the safe current for the appliance starts flowing through the circuit.
[9] Ice is packed in saw dust because –
A.
saw dust will not get melted easily.
B.
saw dust is poor conductor of heat.
C.
saw dust is a good conductor of heat.
D.
saw dust does not stick to the ice.
Ans:
saw dust is poor 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.
[10] A stone is dropped from the roof of a house towards the ground. The kinetic energy of the stone will be maximum:
A.
just after it is dropped
B.
when it is just on the half-way
C.
just before it touches the ground
D.
when it touches the ground
Ans:
just before it touches the ground
Explanation :
When an object reaches the ground it has its maximum value of kinetic energy just before touching the ground. Since kinetic energy + potential energy= Constant; so on reaching ground the potential energy of an object becomes zero (0). The kinetic energy on reaching ground becomes maximum.
[11] What is Hooke’s Law?
A.
Stress is inversely proportional to strain.
B.
Stress is directly proportional to strain.
C.
Stress and strain are dependent on each other.
D.
Stress and strain are independent of each other.
Ans:
Stress is directly proportional to strain.
Explanation :
Hooke’s law is a principle of physics that states that the force (F) needed to extend or compress a spring by some distance X scales linearly with respect to that distance.
[12] Transfer of heat energy from a heater coil to the cooking vessel takes place through the process of-
A.
Convection only
B.
Conduction and convection only
C.
Radiation and convection only
D.
Convection, conduction and radiation
Ans:
Radiation and convection only
Explanation :
Conduction is the transfer of heat energy by direct contact, convection is the movement of heat by actual motion of matter; radiation is the transfer of energy with the help of electromagnetic waves.
[13] A drop of liquid assumes spherical shape because:
A.
Intermolecular forces are strong in liquids
B.
A sphere has the least surface area for a given volume
C.
A sphere has the largest surface area for a given volume
D.
Inter molecular forces are weak in liquids
Ans:
A sphere has the least surface area for a given volume
Explanation :
A drop of liquid assumes spherical shape because a sphere has the least surface area for a given volume.
[14] What are audible sound waves?
A.
Having frequency less than 20 Hz
B.
Having frequency between 20 Hz to 20000 Hz
C.
Having frequency more than 20000 Hz
D.
None of above
Ans:
Having frequency between 20 Hz to 20000 Hz
Explanation :
[15] Sun appears red in colour at sun-rise and sunset due to –
A.
the fact that sun emits only red colour at that time
B.
red light having longer wave length scatters away
C.
that sun Comes out of the mountains
D.
that all other colours scatter away except red
Ans:
that all other colours scatter away except red
Explanation :
According to Rayleigh's law, the intensity of scattered light varies inversely as the fourth power of its wavelength. Sunlight consists of seven colours. Of these, red has the maximum wavelength. During sun- rise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon.
[16] Why does a cannon recoil after firing?
A.
Conservation of energy
B.
Backward thrust of gases produced
C.
NeMon's third law of motion
D.
Newton's first law of motion
Ans:
NeMon's third law of motion
Explanation :
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gases (ejecta), According to Newton's third law. In case of canons, the momentum is transferred to the ground through its mount.
[17] During the motion of a projectile fired from the earth surface, .
A.
its kinetic energy remains constant
B.
its momentum remains constant
C.
vertical component of its velocity remains constant
D.
horizontal component of its velocity remains constant
Ans:
horizontal component of its velocity remains constant
Explanation :
The motion of a projectile is a two-dimensional motion—Horizontal motion and vertical motion—that take place independent of each other. The horizontal velocity of a projectile is constant (a never changing in value). The force of gravity continuously affects the vertical component, so the vertical motion is a uniformly accelerated motion.
[18] A system exhibiting S.H.M. must possess –
A.
Elasticity as well as inertia
B.
Elasticity, inertia and an external force
C.
Elasticity only
D.
Inertia only
Ans:
Elasticity as well as inertia
Explanation :
Basic conditions to execute simple harmonic motion are: (i) There must be an elastic restoring force acting on the system, (ii) the system must have inertia, and (iii) the acceleration of the system should be directly proportional to its displacement and is always directed to mean position.
[19] The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because -
A.
the ringing is not loud enough
B.
the glass of the bell jar absorbs the sound waves
C.
the bell jar is too small
D.
there is no air or any other gas in the bell jar
Ans:
there is no air or any other gas in the bell jar
Explanation :
[20] At hill stations, the boiling point of water will be –
A.
same as at sea level
B.
less than that at sea level
C.
more than that at sea level
D.
equal to the melting point of ice
Ans:
less than that at sea level
Explanation :
The boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure surrounding the liquid. Atmospheric pressure is due to air above any given point. The atmospheric pressure at high altitudes like hill station is less than at the sea level.
[21] The information of brilliant colors in a thin soap film is a consequence of the phenomena of -
A.
Polarization and interference
B.
Diffraction and dispersion
C.
Multiple refraction and dispersion
D.
Multiple reflection and interference
Ans:
Multiple reflection and interference
Explanation :
Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.
[22] Indicate the correct arrangement for electromagnetic radiation in order of their increasing wavelength.
A.
Microwave, infrared, visible. X-rays
B.
X-rays, visible, infrared, microwave
C.
Visible, infrared, microwave, X-rays
D.
X-rays, infrared, visible, microwave
Ans:
X-rays, infrared, visible, microwave
Explanation :
The Electromagnetic spectrum in order of decreasing energy, thus increasing wavelength : Gamma Rays-wavelength: 0.01 nm ; X-rays -1 nm ; Ultra-violet Rays-0.1 micrometres ; Visible Light-Red light : 0.7 micrometres, Violet Light : 0.4 micrometres ; Infrared Radiation-0.01 mm ; Microwaves -less than 10 cm, usually lem ; Radiowaves- Long, Medium and Short Waves : 1am-10 m ; and Very High Frequency (VHF) and Ultra High Frequency (UHF): 10 m-10 cm.
[23] A black body can absorb radiations of ;
A.
lower wavelengths only
B.
intermediate wavelengths only
C.
higher wavelengths only
D.
all wavelengths
Ans:
all wavelengths
Explanation :
A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.
[24] The water from a hand pump is warm in winter because –
A.
Our body is cold in winter and the water appears to be warm
B.
The temperature inside the earth is higher than the atmospheric temperature
C.
The pumping process causes friction which warms up the water
D.
Inside water comes out and absorbs heat from the environment
Ans:
The temperature inside the earth is higher than the atmospheric temperature
Explanation :
In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
[25] When hot liquid is poured into a thick glass tumbler, it cracks because glass –
A.
is a bad conductor of heat so only inner surface expands
B.
has high temperature coefficient of expansion
C.
has a very low specific heat
D.
has low temperature coefficient of expansion
Ans:
is a bad conductor of heat so only inner surface expands
Explanation :
When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.
Explanation :
Hammering a rod will either allow it to become slightly magnetic inlaid along a magnetic field (i.e.North - South) or demagnetize it if laid across the field lines (i.e. East-West). A current passing through a coil will produce a magnetic field.
[2] Which among the following is false about work?
A.
If displacement is zero, work is zero
B.
Work done can be negative
C.
It is a vector quantity
D.
Its unit is Joule
Ans:
It is a vector quantity
Explanation :
Vector, in physics, a quantity that has both magnitude and direction. For example, displacement, velocity, and acceleration are vector quantities, while speed (the magnitude of velocity), time, and mass are scalars.
[3] Which of the following is false?
A.
Most carbon compounds are poor conductors of electricity.
B.
The force of attraction between carbon molecules is not very strong.
C.
The atomic number of carbon is 6.
D.
The earth’s crust has about 2% carbon in the form of minerals.
Ans:
The earth’s crust has about 2% carbon in the form of minerals.
Explanation :
0
[4] Two vectors are said to be equal if –
A.
only their magnitudes are same
B.
only their directions are same
C.
both magnitude and direction are same
D.
magnitudes are same but directions are opposite
Ans:
both magnitude and direction are same
Explanation :
If the magnitude as well as direction of two vectors are equal, then they are known as equal vectors. In other words, two vectors are said to be equal, if they possess equal magnitude and are headed towards the same direction. For two equal vectors, their directed line segments must be parallel.
[5] A real gas can act as an ideal gas in -
A.
high pressure and low temperature
B.
low pressure and high temperature
C.
high pressure and high temperature
D.
low pressure and low temperature
Ans:
low pressure and high temperature
Explanation :
Real gases approximate ideal gases when their pressure is relatively low, and their temperature reasonably high. A real gas deviates increasingly from ideality as it is compressed and cooled to near the point at which it will condense into a liquid.
[6] The Dynamo converts –
A.
Electrical Energy into Mechanical Energy
B.
Mechanical Energy into Magnetic Energy
C.
None of these
D.
Mechanical Energy into Electrical Energy
Ans:
Mechanical Energy into Electrical Energy
Explanation :
Dynamo is a device for converting mechanical energy into electrical energy, especially one that produces direct current. It uses electromagnetic principles to convert mechanical rotation into a pulsing direct electric current through the use of a commutator.
[7] Winch of the following is not true about X-rays?
A.
have low penetrating power
B.
travel with the speed of light
C.
Can be reflected or refracted
D.
can affect photographic plates
Ans:
have low penetrating power
Explanation :
X-rays and gamma rays are photons, i.e. high-energy light-waves. When emitted by a source, for example, radium or cobalt, located outside the body, they easily pass through the body, hence they are usually called penetrating radiation. Because X-rays are penetrating, they can be used in diagnostic medicine to image human bones or human organs made opaque by a dye.
[8] A Fuse wire is characterized by –
A.
High resistance and low melting point
B.
High resistance and high melting point
C.
Low resistance and high melting point
D.
Low resistance and low melting point
Ans:
Low resistance and low melting point
Explanation :
A fuse is a type of low resistance resistor that acts as a sacrificial device to provide over current protection, of either the load or source circuit. Low resistance causes the fuse wire to melt if a current more than the safe current for the appliance starts flowing through the circuit.
[9] Ice is packed in saw dust because –
A.
saw dust will not get melted easily.
B.
saw dust is poor conductor of heat.
C.
saw dust is a good conductor of heat.
D.
saw dust does not stick to the ice.
Ans:
saw dust is poor 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.
[10] A stone is dropped from the roof of a house towards the ground. The kinetic energy of the stone will be maximum:
A.
just after it is dropped
B.
when it is just on the half-way
C.
just before it touches the ground
D.
when it touches the ground
Ans:
just before it touches the ground
Explanation :
When an object reaches the ground it has its maximum value of kinetic energy just before touching the ground. Since kinetic energy + potential energy= Constant; so on reaching ground the potential energy of an object becomes zero (0). The kinetic energy on reaching ground becomes maximum.
[11] What is Hooke’s Law?
A.
Stress is inversely proportional to strain.
B.
Stress is directly proportional to strain.
C.
Stress and strain are dependent on each other.
D.
Stress and strain are independent of each other.
Ans:
Stress is directly proportional to strain.
Explanation :
Hooke’s law is a principle of physics that states that the force (F) needed to extend or compress a spring by some distance X scales linearly with respect to that distance.
[12] Transfer of heat energy from a heater coil to the cooking vessel takes place through the process of-
A.
Convection only
B.
Conduction and convection only
C.
Radiation and convection only
D.
Convection, conduction and radiation
Ans:
Radiation and convection only
Explanation :
Conduction is the transfer of heat energy by direct contact, convection is the movement of heat by actual motion of matter; radiation is the transfer of energy with the help of electromagnetic waves.
[13] A drop of liquid assumes spherical shape because:
A.
Intermolecular forces are strong in liquids
B.
A sphere has the least surface area for a given volume
C.
A sphere has the largest surface area for a given volume
D.
Inter molecular forces are weak in liquids
Ans:
A sphere has the least surface area for a given volume
Explanation :
A drop of liquid assumes spherical shape because a sphere has the least surface area for a given volume.
[14] What are audible sound waves?
A.
Having frequency less than 20 Hz
B.
Having frequency between 20 Hz to 20000 Hz
C.
Having frequency more than 20000 Hz
D.
None of above
Ans:
Having frequency between 20 Hz to 20000 Hz
Explanation :
[15] Sun appears red in colour at sun-rise and sunset due to –
A.
the fact that sun emits only red colour at that time
B.
red light having longer wave length scatters away
C.
that sun Comes out of the mountains
D.
that all other colours scatter away except red
Ans:
that all other colours scatter away except red
Explanation :
According to Rayleigh's law, the intensity of scattered light varies inversely as the fourth power of its wavelength. Sunlight consists of seven colours. Of these, red has the maximum wavelength. During sun- rise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon.
[16] Why does a cannon recoil after firing?
A.
Conservation of energy
B.
Backward thrust of gases produced
C.
NeMon's third law of motion
D.
Newton's first law of motion
Ans:
NeMon's third law of motion
Explanation :
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gases (ejecta), According to Newton's third law. In case of canons, the momentum is transferred to the ground through its mount.
[17] During the motion of a projectile fired from the earth surface, .
A.
its kinetic energy remains constant
B.
its momentum remains constant
C.
vertical component of its velocity remains constant
D.
horizontal component of its velocity remains constant
Ans:
horizontal component of its velocity remains constant
Explanation :
The motion of a projectile is a two-dimensional motion—Horizontal motion and vertical motion—that take place independent of each other. The horizontal velocity of a projectile is constant (a never changing in value). The force of gravity continuously affects the vertical component, so the vertical motion is a uniformly accelerated motion.
[18] A system exhibiting S.H.M. must possess –
A.
Elasticity as well as inertia
B.
Elasticity, inertia and an external force
C.
Elasticity only
D.
Inertia only
Ans:
Elasticity as well as inertia
Explanation :
Basic conditions to execute simple harmonic motion are: (i) There must be an elastic restoring force acting on the system, (ii) the system must have inertia, and (iii) the acceleration of the system should be directly proportional to its displacement and is always directed to mean position.
[19] The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because -
A.
the ringing is not loud enough
B.
the glass of the bell jar absorbs the sound waves
C.
the bell jar is too small
D.
there is no air or any other gas in the bell jar
Ans:
there is no air or any other gas in the bell jar
Explanation :
[20] At hill stations, the boiling point of water will be –
A.
same as at sea level
B.
less than that at sea level
C.
more than that at sea level
D.
equal to the melting point of ice
Ans:
less than that at sea level
Explanation :
The boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure surrounding the liquid. Atmospheric pressure is due to air above any given point. The atmospheric pressure at high altitudes like hill station is less than at the sea level.
[21] The information of brilliant colors in a thin soap film is a consequence of the phenomena of -
A.
Polarization and interference
B.
Diffraction and dispersion
C.
Multiple refraction and dispersion
D.
Multiple reflection and interference
Ans:
Multiple reflection and interference
Explanation :
Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.
[22] Indicate the correct arrangement for electromagnetic radiation in order of their increasing wavelength.
A.
Microwave, infrared, visible. X-rays
B.
X-rays, visible, infrared, microwave
C.
Visible, infrared, microwave, X-rays
D.
X-rays, infrared, visible, microwave
Ans:
X-rays, infrared, visible, microwave
Explanation :
The Electromagnetic spectrum in order of decreasing energy, thus increasing wavelength : Gamma Rays-wavelength: 0.01 nm ; X-rays -1 nm ; Ultra-violet Rays-0.1 micrometres ; Visible Light-Red light : 0.7 micrometres, Violet Light : 0.4 micrometres ; Infrared Radiation-0.01 mm ; Microwaves -less than 10 cm, usually lem ; Radiowaves- Long, Medium and Short Waves : 1am-10 m ; and Very High Frequency (VHF) and Ultra High Frequency (UHF): 10 m-10 cm.
[23] A black body can absorb radiations of ;
A.
lower wavelengths only
B.
intermediate wavelengths only
C.
higher wavelengths only
D.
all wavelengths
Ans:
all wavelengths
Explanation :
A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.
[24] The water from a hand pump is warm in winter because –
A.
Our body is cold in winter and the water appears to be warm
B.
The temperature inside the earth is higher than the atmospheric temperature
C.
The pumping process causes friction which warms up the water
D.
Inside water comes out and absorbs heat from the environment
Ans:
The temperature inside the earth is higher than the atmospheric temperature
Explanation :
In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
[25] When hot liquid is poured into a thick glass tumbler, it cracks because glass –
A.
is a bad conductor of heat so only inner surface expands
B.
has high temperature coefficient of expansion
C.
has a very low specific heat
D.
has low temperature coefficient of expansion
Ans:
is a bad conductor of heat so only inner surface expands
Explanation :
When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.
Explanation :
0
[4] Two vectors are said to be equal if –
A.
only their magnitudes are same
B.
only their directions are same
C.
both magnitude and direction are same
D.
magnitudes are same but directions are opposite
Ans:
both magnitude and direction are same
Explanation :
If the magnitude as well as direction of two vectors are equal, then they are known as equal vectors. In other words, two vectors are said to be equal, if they possess equal magnitude and are headed towards the same direction. For two equal vectors, their directed line segments must be parallel.
[5] A real gas can act as an ideal gas in -
A.
high pressure and low temperature
B.
low pressure and high temperature
C.
high pressure and high temperature
D.
low pressure and low temperature
Ans:
low pressure and high temperature
Explanation :
Real gases approximate ideal gases when their pressure is relatively low, and their temperature reasonably high. A real gas deviates increasingly from ideality as it is compressed and cooled to near the point at which it will condense into a liquid.
[6] The Dynamo converts –
A.
Electrical Energy into Mechanical Energy
B.
Mechanical Energy into Magnetic Energy
C.
None of these
D.
Mechanical Energy into Electrical Energy
Ans:
Mechanical Energy into Electrical Energy
Explanation :
Dynamo is a device for converting mechanical energy into electrical energy, especially one that produces direct current. It uses electromagnetic principles to convert mechanical rotation into a pulsing direct electric current through the use of a commutator.
[7] Winch of the following is not true about X-rays?
A.
have low penetrating power
B.
travel with the speed of light
C.
Can be reflected or refracted
D.
can affect photographic plates
Ans:
have low penetrating power
Explanation :
X-rays and gamma rays are photons, i.e. high-energy light-waves. When emitted by a source, for example, radium or cobalt, located outside the body, they easily pass through the body, hence they are usually called penetrating radiation. Because X-rays are penetrating, they can be used in diagnostic medicine to image human bones or human organs made opaque by a dye.
[8] A Fuse wire is characterized by –
A.
High resistance and low melting point
B.
High resistance and high melting point
C.
Low resistance and high melting point
D.
Low resistance and low melting point
Ans:
Low resistance and low melting point
Explanation :
A fuse is a type of low resistance resistor that acts as a sacrificial device to provide over current protection, of either the load or source circuit. Low resistance causes the fuse wire to melt if a current more than the safe current for the appliance starts flowing through the circuit.
[9] Ice is packed in saw dust because –
A.
saw dust will not get melted easily.
B.
saw dust is poor conductor of heat.
C.
saw dust is a good conductor of heat.
D.
saw dust does not stick to the ice.
Ans:
saw dust is poor 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.
[10] A stone is dropped from the roof of a house towards the ground. The kinetic energy of the stone will be maximum:
A.
just after it is dropped
B.
when it is just on the half-way
C.
just before it touches the ground
D.
when it touches the ground
Ans:
just before it touches the ground
Explanation :
When an object reaches the ground it has its maximum value of kinetic energy just before touching the ground. Since kinetic energy + potential energy= Constant; so on reaching ground the potential energy of an object becomes zero (0). The kinetic energy on reaching ground becomes maximum.
[11] What is Hooke’s Law?
A.
Stress is inversely proportional to strain.
B.
Stress is directly proportional to strain.
C.
Stress and strain are dependent on each other.
D.
Stress and strain are independent of each other.
Ans:
Stress is directly proportional to strain.
Explanation :
Hooke’s law is a principle of physics that states that the force (F) needed to extend or compress a spring by some distance X scales linearly with respect to that distance.
[12] Transfer of heat energy from a heater coil to the cooking vessel takes place through the process of-
A.
Convection only
B.
Conduction and convection only
C.
Radiation and convection only
D.
Convection, conduction and radiation
Ans:
Radiation and convection only
Explanation :
Conduction is the transfer of heat energy by direct contact, convection is the movement of heat by actual motion of matter; radiation is the transfer of energy with the help of electromagnetic waves.
[13] A drop of liquid assumes spherical shape because:
A.
Intermolecular forces are strong in liquids
B.
A sphere has the least surface area for a given volume
C.
A sphere has the largest surface area for a given volume
D.
Inter molecular forces are weak in liquids
Ans:
A sphere has the least surface area for a given volume
Explanation :
A drop of liquid assumes spherical shape because a sphere has the least surface area for a given volume.
[14] What are audible sound waves?
A.
Having frequency less than 20 Hz
B.
Having frequency between 20 Hz to 20000 Hz
C.
Having frequency more than 20000 Hz
D.
None of above
Ans:
Having frequency between 20 Hz to 20000 Hz
Explanation :
[15] Sun appears red in colour at sun-rise and sunset due to –
A.
the fact that sun emits only red colour at that time
B.
red light having longer wave length scatters away
C.
that sun Comes out of the mountains
D.
that all other colours scatter away except red
Ans:
that all other colours scatter away except red
Explanation :
According to Rayleigh's law, the intensity of scattered light varies inversely as the fourth power of its wavelength. Sunlight consists of seven colours. Of these, red has the maximum wavelength. During sun- rise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon.
[16] Why does a cannon recoil after firing?
A.
Conservation of energy
B.
Backward thrust of gases produced
C.
NeMon's third law of motion
D.
Newton's first law of motion
Ans:
NeMon's third law of motion
Explanation :
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gases (ejecta), According to Newton's third law. In case of canons, the momentum is transferred to the ground through its mount.
[17] During the motion of a projectile fired from the earth surface, .
A.
its kinetic energy remains constant
B.
its momentum remains constant
C.
vertical component of its velocity remains constant
D.
horizontal component of its velocity remains constant
Ans:
horizontal component of its velocity remains constant
Explanation :
The motion of a projectile is a two-dimensional motion—Horizontal motion and vertical motion—that take place independent of each other. The horizontal velocity of a projectile is constant (a never changing in value). The force of gravity continuously affects the vertical component, so the vertical motion is a uniformly accelerated motion.
[18] A system exhibiting S.H.M. must possess –
A.
Elasticity as well as inertia
B.
Elasticity, inertia and an external force
C.
Elasticity only
D.
Inertia only
Ans:
Elasticity as well as inertia
Explanation :
Basic conditions to execute simple harmonic motion are: (i) There must be an elastic restoring force acting on the system, (ii) the system must have inertia, and (iii) the acceleration of the system should be directly proportional to its displacement and is always directed to mean position.
[19] The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because -
A.
the ringing is not loud enough
B.
the glass of the bell jar absorbs the sound waves
C.
the bell jar is too small
D.
there is no air or any other gas in the bell jar
Ans:
there is no air or any other gas in the bell jar
Explanation :
[20] At hill stations, the boiling point of water will be –
A.
same as at sea level
B.
less than that at sea level
C.
more than that at sea level
D.
equal to the melting point of ice
Ans:
less than that at sea level
Explanation :
The boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure surrounding the liquid. Atmospheric pressure is due to air above any given point. The atmospheric pressure at high altitudes like hill station is less than at the sea level.
[21] The information of brilliant colors in a thin soap film is a consequence of the phenomena of -
A.
Polarization and interference
B.
Diffraction and dispersion
C.
Multiple refraction and dispersion
D.
Multiple reflection and interference
Ans:
Multiple reflection and interference
Explanation :
Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.
[22] Indicate the correct arrangement for electromagnetic radiation in order of their increasing wavelength.
A.
Microwave, infrared, visible. X-rays
B.
X-rays, visible, infrared, microwave
C.
Visible, infrared, microwave, X-rays
D.
X-rays, infrared, visible, microwave
Ans:
X-rays, infrared, visible, microwave
Explanation :
The Electromagnetic spectrum in order of decreasing energy, thus increasing wavelength : Gamma Rays-wavelength: 0.01 nm ; X-rays -1 nm ; Ultra-violet Rays-0.1 micrometres ; Visible Light-Red light : 0.7 micrometres, Violet Light : 0.4 micrometres ; Infrared Radiation-0.01 mm ; Microwaves -less than 10 cm, usually lem ; Radiowaves- Long, Medium and Short Waves : 1am-10 m ; and Very High Frequency (VHF) and Ultra High Frequency (UHF): 10 m-10 cm.
[23] A black body can absorb radiations of ;
A.
lower wavelengths only
B.
intermediate wavelengths only
C.
higher wavelengths only
D.
all wavelengths
Ans:
all wavelengths
Explanation :
A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.
[24] The water from a hand pump is warm in winter because –
A.
Our body is cold in winter and the water appears to be warm
B.
The temperature inside the earth is higher than the atmospheric temperature
C.
The pumping process causes friction which warms up the water
D.
Inside water comes out and absorbs heat from the environment
Ans:
The temperature inside the earth is higher than the atmospheric temperature
Explanation :
In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
[25] When hot liquid is poured into a thick glass tumbler, it cracks because glass –
A.
is a bad conductor of heat so only inner surface expands
B.
has high temperature coefficient of expansion
C.
has a very low specific heat
D.
has low temperature coefficient of expansion
Ans:
is a bad conductor of heat so only inner surface expands
Explanation :
When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.
Explanation :
Real gases approximate ideal gases when their pressure is relatively low, and their temperature reasonably high. A real gas deviates increasingly from ideality as it is compressed and cooled to near the point at which it will condense into a liquid.
[6] The Dynamo converts –
A.
Electrical Energy into Mechanical Energy
B.
Mechanical Energy into Magnetic Energy
C.
None of these
D.
Mechanical Energy into Electrical Energy
Ans:
Mechanical Energy into Electrical Energy
Explanation :
Dynamo is a device for converting mechanical energy into electrical energy, especially one that produces direct current. It uses electromagnetic principles to convert mechanical rotation into a pulsing direct electric current through the use of a commutator.
[7] Winch of the following is not true about X-rays?
A.
have low penetrating power
B.
travel with the speed of light
C.
Can be reflected or refracted
D.
can affect photographic plates
Ans:
have low penetrating power
Explanation :
X-rays and gamma rays are photons, i.e. high-energy light-waves. When emitted by a source, for example, radium or cobalt, located outside the body, they easily pass through the body, hence they are usually called penetrating radiation. Because X-rays are penetrating, they can be used in diagnostic medicine to image human bones or human organs made opaque by a dye.
[8] A Fuse wire is characterized by –
A.
High resistance and low melting point
B.
High resistance and high melting point
C.
Low resistance and high melting point
D.
Low resistance and low melting point
Ans:
Low resistance and low melting point
Explanation :
A fuse is a type of low resistance resistor that acts as a sacrificial device to provide over current protection, of either the load or source circuit. Low resistance causes the fuse wire to melt if a current more than the safe current for the appliance starts flowing through the circuit.
[9] Ice is packed in saw dust because –
A.
saw dust will not get melted easily.
B.
saw dust is poor conductor of heat.
C.
saw dust is a good conductor of heat.
D.
saw dust does not stick to the ice.
Ans:
saw dust is poor 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.
[10] A stone is dropped from the roof of a house towards the ground. The kinetic energy of the stone will be maximum:
A.
just after it is dropped
B.
when it is just on the half-way
C.
just before it touches the ground
D.
when it touches the ground
Ans:
just before it touches the ground
Explanation :
When an object reaches the ground it has its maximum value of kinetic energy just before touching the ground. Since kinetic energy + potential energy= Constant; so on reaching ground the potential energy of an object becomes zero (0). The kinetic energy on reaching ground becomes maximum.
[11] What is Hooke’s Law?
A.
Stress is inversely proportional to strain.
B.
Stress is directly proportional to strain.
C.
Stress and strain are dependent on each other.
D.
Stress and strain are independent of each other.
Ans:
Stress is directly proportional to strain.
Explanation :
Hooke’s law is a principle of physics that states that the force (F) needed to extend or compress a spring by some distance X scales linearly with respect to that distance.
[12] Transfer of heat energy from a heater coil to the cooking vessel takes place through the process of-
A.
Convection only
B.
Conduction and convection only
C.
Radiation and convection only
D.
Convection, conduction and radiation
Ans:
Radiation and convection only
Explanation :
Conduction is the transfer of heat energy by direct contact, convection is the movement of heat by actual motion of matter; radiation is the transfer of energy with the help of electromagnetic waves.
[13] A drop of liquid assumes spherical shape because:
A.
Intermolecular forces are strong in liquids
B.
A sphere has the least surface area for a given volume
C.
A sphere has the largest surface area for a given volume
D.
Inter molecular forces are weak in liquids
Ans:
A sphere has the least surface area for a given volume
Explanation :
A drop of liquid assumes spherical shape because a sphere has the least surface area for a given volume.
[14] What are audible sound waves?
A.
Having frequency less than 20 Hz
B.
Having frequency between 20 Hz to 20000 Hz
C.
Having frequency more than 20000 Hz
D.
None of above
Ans:
Having frequency between 20 Hz to 20000 Hz
Explanation :
[15] Sun appears red in colour at sun-rise and sunset due to –
A.
the fact that sun emits only red colour at that time
B.
red light having longer wave length scatters away
C.
that sun Comes out of the mountains
D.
that all other colours scatter away except red
Ans:
that all other colours scatter away except red
Explanation :
According to Rayleigh's law, the intensity of scattered light varies inversely as the fourth power of its wavelength. Sunlight consists of seven colours. Of these, red has the maximum wavelength. During sun- rise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon.
[16] Why does a cannon recoil after firing?
A.
Conservation of energy
B.
Backward thrust of gases produced
C.
NeMon's third law of motion
D.
Newton's first law of motion
Ans:
NeMon's third law of motion
Explanation :
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gases (ejecta), According to Newton's third law. In case of canons, the momentum is transferred to the ground through its mount.
[17] During the motion of a projectile fired from the earth surface, .
A.
its kinetic energy remains constant
B.
its momentum remains constant
C.
vertical component of its velocity remains constant
D.
horizontal component of its velocity remains constant
Ans:
horizontal component of its velocity remains constant
Explanation :
The motion of a projectile is a two-dimensional motion—Horizontal motion and vertical motion—that take place independent of each other. The horizontal velocity of a projectile is constant (a never changing in value). The force of gravity continuously affects the vertical component, so the vertical motion is a uniformly accelerated motion.
[18] A system exhibiting S.H.M. must possess –
A.
Elasticity as well as inertia
B.
Elasticity, inertia and an external force
C.
Elasticity only
D.
Inertia only
Ans:
Elasticity as well as inertia
Explanation :
Basic conditions to execute simple harmonic motion are: (i) There must be an elastic restoring force acting on the system, (ii) the system must have inertia, and (iii) the acceleration of the system should be directly proportional to its displacement and is always directed to mean position.
[19] The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because -
A.
the ringing is not loud enough
B.
the glass of the bell jar absorbs the sound waves
C.
the bell jar is too small
D.
there is no air or any other gas in the bell jar
Ans:
there is no air or any other gas in the bell jar
Explanation :
[20] At hill stations, the boiling point of water will be –
A.
same as at sea level
B.
less than that at sea level
C.
more than that at sea level
D.
equal to the melting point of ice
Ans:
less than that at sea level
Explanation :
The boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure surrounding the liquid. Atmospheric pressure is due to air above any given point. The atmospheric pressure at high altitudes like hill station is less than at the sea level.
[21] The information of brilliant colors in a thin soap film is a consequence of the phenomena of -
A.
Polarization and interference
B.
Diffraction and dispersion
C.
Multiple refraction and dispersion
D.
Multiple reflection and interference
Ans:
Multiple reflection and interference
Explanation :
Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.
[22] Indicate the correct arrangement for electromagnetic radiation in order of their increasing wavelength.
A.
Microwave, infrared, visible. X-rays
B.
X-rays, visible, infrared, microwave
C.
Visible, infrared, microwave, X-rays
D.
X-rays, infrared, visible, microwave
Ans:
X-rays, infrared, visible, microwave
Explanation :
The Electromagnetic spectrum in order of decreasing energy, thus increasing wavelength : Gamma Rays-wavelength: 0.01 nm ; X-rays -1 nm ; Ultra-violet Rays-0.1 micrometres ; Visible Light-Red light : 0.7 micrometres, Violet Light : 0.4 micrometres ; Infrared Radiation-0.01 mm ; Microwaves -less than 10 cm, usually lem ; Radiowaves- Long, Medium and Short Waves : 1am-10 m ; and Very High Frequency (VHF) and Ultra High Frequency (UHF): 10 m-10 cm.
[23] A black body can absorb radiations of ;
A.
lower wavelengths only
B.
intermediate wavelengths only
C.
higher wavelengths only
D.
all wavelengths
Ans:
all wavelengths
Explanation :
A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.
[24] The water from a hand pump is warm in winter because –
A.
Our body is cold in winter and the water appears to be warm
B.
The temperature inside the earth is higher than the atmospheric temperature
C.
The pumping process causes friction which warms up the water
D.
Inside water comes out and absorbs heat from the environment
Ans:
The temperature inside the earth is higher than the atmospheric temperature
Explanation :
In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
[25] When hot liquid is poured into a thick glass tumbler, it cracks because glass –
A.
is a bad conductor of heat so only inner surface expands
B.
has high temperature coefficient of expansion
C.
has a very low specific heat
D.
has low temperature coefficient of expansion
Ans:
is a bad conductor of heat so only inner surface expands
Explanation :
When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.
Explanation :
X-rays and gamma rays are photons, i.e. high-energy light-waves. When emitted by a source, for example, radium or cobalt, located outside the body, they easily pass through the body, hence they are usually called penetrating radiation. Because X-rays are penetrating, they can be used in diagnostic medicine to image human bones or human organs made opaque by a dye.
[8] A Fuse wire is characterized by –
A.
High resistance and low melting point
B.
High resistance and high melting point
C.
Low resistance and high melting point
D.
Low resistance and low melting point
Ans:
Low resistance and low melting point
Explanation :
A fuse is a type of low resistance resistor that acts as a sacrificial device to provide over current protection, of either the load or source circuit. Low resistance causes the fuse wire to melt if a current more than the safe current for the appliance starts flowing through the circuit.
[9] Ice is packed in saw dust because –
A.
saw dust will not get melted easily.
B.
saw dust is poor conductor of heat.
C.
saw dust is a good conductor of heat.
D.
saw dust does not stick to the ice.
Ans:
saw dust is poor 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.
[10] A stone is dropped from the roof of a house towards the ground. The kinetic energy of the stone will be maximum:
A.
just after it is dropped
B.
when it is just on the half-way
C.
just before it touches the ground
D.
when it touches the ground
Ans:
just before it touches the ground
Explanation :
When an object reaches the ground it has its maximum value of kinetic energy just before touching the ground. Since kinetic energy + potential energy= Constant; so on reaching ground the potential energy of an object becomes zero (0). The kinetic energy on reaching ground becomes maximum.
[11] What is Hooke’s Law?
A.
Stress is inversely proportional to strain.
B.
Stress is directly proportional to strain.
C.
Stress and strain are dependent on each other.
D.
Stress and strain are independent of each other.
Ans:
Stress is directly proportional to strain.
Explanation :
Hooke’s law is a principle of physics that states that the force (F) needed to extend or compress a spring by some distance X scales linearly with respect to that distance.
[12] Transfer of heat energy from a heater coil to the cooking vessel takes place through the process of-
A.
Convection only
B.
Conduction and convection only
C.
Radiation and convection only
D.
Convection, conduction and radiation
Ans:
Radiation and convection only
Explanation :
Conduction is the transfer of heat energy by direct contact, convection is the movement of heat by actual motion of matter; radiation is the transfer of energy with the help of electromagnetic waves.
[13] A drop of liquid assumes spherical shape because:
A.
Intermolecular forces are strong in liquids
B.
A sphere has the least surface area for a given volume
C.
A sphere has the largest surface area for a given volume
D.
Inter molecular forces are weak in liquids
Ans:
A sphere has the least surface area for a given volume
Explanation :
A drop of liquid assumes spherical shape because a sphere has the least surface area for a given volume.
[14] What are audible sound waves?
A.
Having frequency less than 20 Hz
B.
Having frequency between 20 Hz to 20000 Hz
C.
Having frequency more than 20000 Hz
D.
None of above
Ans:
Having frequency between 20 Hz to 20000 Hz
Explanation :
[15] Sun appears red in colour at sun-rise and sunset due to –
A.
the fact that sun emits only red colour at that time
B.
red light having longer wave length scatters away
C.
that sun Comes out of the mountains
D.
that all other colours scatter away except red
Ans:
that all other colours scatter away except red
Explanation :
According to Rayleigh's law, the intensity of scattered light varies inversely as the fourth power of its wavelength. Sunlight consists of seven colours. Of these, red has the maximum wavelength. During sun- rise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon.
[16] Why does a cannon recoil after firing?
A.
Conservation of energy
B.
Backward thrust of gases produced
C.
NeMon's third law of motion
D.
Newton's first law of motion
Ans:
NeMon's third law of motion
Explanation :
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gases (ejecta), According to Newton's third law. In case of canons, the momentum is transferred to the ground through its mount.
[17] During the motion of a projectile fired from the earth surface, .
A.
its kinetic energy remains constant
B.
its momentum remains constant
C.
vertical component of its velocity remains constant
D.
horizontal component of its velocity remains constant
Ans:
horizontal component of its velocity remains constant
Explanation :
The motion of a projectile is a two-dimensional motion—Horizontal motion and vertical motion—that take place independent of each other. The horizontal velocity of a projectile is constant (a never changing in value). The force of gravity continuously affects the vertical component, so the vertical motion is a uniformly accelerated motion.
[18] A system exhibiting S.H.M. must possess –
A.
Elasticity as well as inertia
B.
Elasticity, inertia and an external force
C.
Elasticity only
D.
Inertia only
Ans:
Elasticity as well as inertia
Explanation :
Basic conditions to execute simple harmonic motion are: (i) There must be an elastic restoring force acting on the system, (ii) the system must have inertia, and (iii) the acceleration of the system should be directly proportional to its displacement and is always directed to mean position.
[19] The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because -
A.
the ringing is not loud enough
B.
the glass of the bell jar absorbs the sound waves
C.
the bell jar is too small
D.
there is no air or any other gas in the bell jar
Ans:
there is no air or any other gas in the bell jar
Explanation :
[20] At hill stations, the boiling point of water will be –
A.
same as at sea level
B.
less than that at sea level
C.
more than that at sea level
D.
equal to the melting point of ice
Ans:
less than that at sea level
Explanation :
The boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure surrounding the liquid. Atmospheric pressure is due to air above any given point. The atmospheric pressure at high altitudes like hill station is less than at the sea level.
[21] The information of brilliant colors in a thin soap film is a consequence of the phenomena of -
A.
Polarization and interference
B.
Diffraction and dispersion
C.
Multiple refraction and dispersion
D.
Multiple reflection and interference
Ans:
Multiple reflection and interference
Explanation :
Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.
[22] Indicate the correct arrangement for electromagnetic radiation in order of their increasing wavelength.
A.
Microwave, infrared, visible. X-rays
B.
X-rays, visible, infrared, microwave
C.
Visible, infrared, microwave, X-rays
D.
X-rays, infrared, visible, microwave
Ans:
X-rays, infrared, visible, microwave
Explanation :
The Electromagnetic spectrum in order of decreasing energy, thus increasing wavelength : Gamma Rays-wavelength: 0.01 nm ; X-rays -1 nm ; Ultra-violet Rays-0.1 micrometres ; Visible Light-Red light : 0.7 micrometres, Violet Light : 0.4 micrometres ; Infrared Radiation-0.01 mm ; Microwaves -less than 10 cm, usually lem ; Radiowaves- Long, Medium and Short Waves : 1am-10 m ; and Very High Frequency (VHF) and Ultra High Frequency (UHF): 10 m-10 cm.
[23] A black body can absorb radiations of ;
A.
lower wavelengths only
B.
intermediate wavelengths only
C.
higher wavelengths only
D.
all wavelengths
Ans:
all wavelengths
Explanation :
A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.
[24] The water from a hand pump is warm in winter because –
A.
Our body is cold in winter and the water appears to be warm
B.
The temperature inside the earth is higher than the atmospheric temperature
C.
The pumping process causes friction which warms up the water
D.
Inside water comes out and absorbs heat from the environment
Ans:
The temperature inside the earth is higher than the atmospheric temperature
Explanation :
In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
[25] When hot liquid is poured into a thick glass tumbler, it cracks because glass –
A.
is a bad conductor of heat so only inner surface expands
B.
has high temperature coefficient of expansion
C.
has a very low specific heat
D.
has low temperature coefficient of expansion
Ans:
is a bad conductor of heat so only inner surface expands
Explanation :
When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.
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.
[10] A stone is dropped from the roof of a house towards the ground. The kinetic energy of the stone will be maximum:
A.
just after it is dropped
B.
when it is just on the half-way
C.
just before it touches the ground
D.
when it touches the ground
Ans:
just before it touches the ground
Explanation :
When an object reaches the ground it has its maximum value of kinetic energy just before touching the ground. Since kinetic energy + potential energy= Constant; so on reaching ground the potential energy of an object becomes zero (0). The kinetic energy on reaching ground becomes maximum.
[11] What is Hooke’s Law?
A.
Stress is inversely proportional to strain.
B.
Stress is directly proportional to strain.
C.
Stress and strain are dependent on each other.
D.
Stress and strain are independent of each other.
Ans:
Stress is directly proportional to strain.
Explanation :
Hooke’s law is a principle of physics that states that the force (F) needed to extend or compress a spring by some distance X scales linearly with respect to that distance.
[12] Transfer of heat energy from a heater coil to the cooking vessel takes place through the process of-
A.
Convection only
B.
Conduction and convection only
C.
Radiation and convection only
D.
Convection, conduction and radiation
Ans:
Radiation and convection only
Explanation :
Conduction is the transfer of heat energy by direct contact, convection is the movement of heat by actual motion of matter; radiation is the transfer of energy with the help of electromagnetic waves.
[13] A drop of liquid assumes spherical shape because:
A.
Intermolecular forces are strong in liquids
B.
A sphere has the least surface area for a given volume
C.
A sphere has the largest surface area for a given volume
D.
Inter molecular forces are weak in liquids
Ans:
A sphere has the least surface area for a given volume
Explanation :
A drop of liquid assumes spherical shape because a sphere has the least surface area for a given volume.
[14] What are audible sound waves?
A.
Having frequency less than 20 Hz
B.
Having frequency between 20 Hz to 20000 Hz
C.
Having frequency more than 20000 Hz
D.
None of above
Ans:
Having frequency between 20 Hz to 20000 Hz
Explanation :
[15] Sun appears red in colour at sun-rise and sunset due to –
A.
the fact that sun emits only red colour at that time
B.
red light having longer wave length scatters away
C.
that sun Comes out of the mountains
D.
that all other colours scatter away except red
Ans:
that all other colours scatter away except red
Explanation :
According to Rayleigh's law, the intensity of scattered light varies inversely as the fourth power of its wavelength. Sunlight consists of seven colours. Of these, red has the maximum wavelength. During sun- rise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon.
[16] Why does a cannon recoil after firing?
A.
Conservation of energy
B.
Backward thrust of gases produced
C.
NeMon's third law of motion
D.
Newton's first law of motion
Ans:
NeMon's third law of motion
Explanation :
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gases (ejecta), According to Newton's third law. In case of canons, the momentum is transferred to the ground through its mount.
[17] During the motion of a projectile fired from the earth surface, .
A.
its kinetic energy remains constant
B.
its momentum remains constant
C.
vertical component of its velocity remains constant
D.
horizontal component of its velocity remains constant
Ans:
horizontal component of its velocity remains constant
Explanation :
The motion of a projectile is a two-dimensional motion—Horizontal motion and vertical motion—that take place independent of each other. The horizontal velocity of a projectile is constant (a never changing in value). The force of gravity continuously affects the vertical component, so the vertical motion is a uniformly accelerated motion.
[18] A system exhibiting S.H.M. must possess –
A.
Elasticity as well as inertia
B.
Elasticity, inertia and an external force
C.
Elasticity only
D.
Inertia only
Ans:
Elasticity as well as inertia
Explanation :
Basic conditions to execute simple harmonic motion are: (i) There must be an elastic restoring force acting on the system, (ii) the system must have inertia, and (iii) the acceleration of the system should be directly proportional to its displacement and is always directed to mean position.
[19] The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because -
A.
the ringing is not loud enough
B.
the glass of the bell jar absorbs the sound waves
C.
the bell jar is too small
D.
there is no air or any other gas in the bell jar
Ans:
there is no air or any other gas in the bell jar
Explanation :
[20] At hill stations, the boiling point of water will be –
A.
same as at sea level
B.
less than that at sea level
C.
more than that at sea level
D.
equal to the melting point of ice
Ans:
less than that at sea level
Explanation :
The boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure surrounding the liquid. Atmospheric pressure is due to air above any given point. The atmospheric pressure at high altitudes like hill station is less than at the sea level.
[21] The information of brilliant colors in a thin soap film is a consequence of the phenomena of -
A.
Polarization and interference
B.
Diffraction and dispersion
C.
Multiple refraction and dispersion
D.
Multiple reflection and interference
Ans:
Multiple reflection and interference
Explanation :
Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.
[22] Indicate the correct arrangement for electromagnetic radiation in order of their increasing wavelength.
A.
Microwave, infrared, visible. X-rays
B.
X-rays, visible, infrared, microwave
C.
Visible, infrared, microwave, X-rays
D.
X-rays, infrared, visible, microwave
Ans:
X-rays, infrared, visible, microwave
Explanation :
The Electromagnetic spectrum in order of decreasing energy, thus increasing wavelength : Gamma Rays-wavelength: 0.01 nm ; X-rays -1 nm ; Ultra-violet Rays-0.1 micrometres ; Visible Light-Red light : 0.7 micrometres, Violet Light : 0.4 micrometres ; Infrared Radiation-0.01 mm ; Microwaves -less than 10 cm, usually lem ; Radiowaves- Long, Medium and Short Waves : 1am-10 m ; and Very High Frequency (VHF) and Ultra High Frequency (UHF): 10 m-10 cm.
[23] A black body can absorb radiations of ;
A.
lower wavelengths only
B.
intermediate wavelengths only
C.
higher wavelengths only
D.
all wavelengths
Ans:
all wavelengths
Explanation :
A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.
[24] The water from a hand pump is warm in winter because –
A.
Our body is cold in winter and the water appears to be warm
B.
The temperature inside the earth is higher than the atmospheric temperature
C.
The pumping process causes friction which warms up the water
D.
Inside water comes out and absorbs heat from the environment
Ans:
The temperature inside the earth is higher than the atmospheric temperature
Explanation :
In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
[25] When hot liquid is poured into a thick glass tumbler, it cracks because glass –
A.
is a bad conductor of heat so only inner surface expands
B.
has high temperature coefficient of expansion
C.
has a very low specific heat
D.
has low temperature coefficient of expansion
Ans:
is a bad conductor of heat so only inner surface expands
Explanation :
When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.
Explanation :
Hooke’s law is a principle of physics that states that the force (F) needed to extend or compress a spring by some distance X scales linearly with respect to that distance.
[12] Transfer of heat energy from a heater coil to the cooking vessel takes place through the process of-
A.
Convection only
B.
Conduction and convection only
C.
Radiation and convection only
D.
Convection, conduction and radiation
Ans:
Radiation and convection only
Explanation :
Conduction is the transfer of heat energy by direct contact, convection is the movement of heat by actual motion of matter; radiation is the transfer of energy with the help of electromagnetic waves.
[13] A drop of liquid assumes spherical shape because:
A.
Intermolecular forces are strong in liquids
B.
A sphere has the least surface area for a given volume
C.
A sphere has the largest surface area for a given volume
D.
Inter molecular forces are weak in liquids
Ans:
A sphere has the least surface area for a given volume
Explanation :
A drop of liquid assumes spherical shape because a sphere has the least surface area for a given volume.
[14] What are audible sound waves?
A.
Having frequency less than 20 Hz
B.
Having frequency between 20 Hz to 20000 Hz
C.
Having frequency more than 20000 Hz
D.
None of above
Ans:
Having frequency between 20 Hz to 20000 Hz
Explanation :
[15] Sun appears red in colour at sun-rise and sunset due to –
A.
the fact that sun emits only red colour at that time
B.
red light having longer wave length scatters away
C.
that sun Comes out of the mountains
D.
that all other colours scatter away except red
Ans:
that all other colours scatter away except red
Explanation :
According to Rayleigh's law, the intensity of scattered light varies inversely as the fourth power of its wavelength. Sunlight consists of seven colours. Of these, red has the maximum wavelength. During sun- rise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon.
[16] Why does a cannon recoil after firing?
A.
Conservation of energy
B.
Backward thrust of gases produced
C.
NeMon's third law of motion
D.
Newton's first law of motion
Ans:
NeMon's third law of motion
Explanation :
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gases (ejecta), According to Newton's third law. In case of canons, the momentum is transferred to the ground through its mount.
[17] During the motion of a projectile fired from the earth surface, .
A.
its kinetic energy remains constant
B.
its momentum remains constant
C.
vertical component of its velocity remains constant
D.
horizontal component of its velocity remains constant
Ans:
horizontal component of its velocity remains constant
Explanation :
The motion of a projectile is a two-dimensional motion—Horizontal motion and vertical motion—that take place independent of each other. The horizontal velocity of a projectile is constant (a never changing in value). The force of gravity continuously affects the vertical component, so the vertical motion is a uniformly accelerated motion.
[18] A system exhibiting S.H.M. must possess –
A.
Elasticity as well as inertia
B.
Elasticity, inertia and an external force
C.
Elasticity only
D.
Inertia only
Ans:
Elasticity as well as inertia
Explanation :
Basic conditions to execute simple harmonic motion are: (i) There must be an elastic restoring force acting on the system, (ii) the system must have inertia, and (iii) the acceleration of the system should be directly proportional to its displacement and is always directed to mean position.
[19] The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because -
A.
the ringing is not loud enough
B.
the glass of the bell jar absorbs the sound waves
C.
the bell jar is too small
D.
there is no air or any other gas in the bell jar
Ans:
there is no air or any other gas in the bell jar
Explanation :
[20] At hill stations, the boiling point of water will be –
A.
same as at sea level
B.
less than that at sea level
C.
more than that at sea level
D.
equal to the melting point of ice
Ans:
less than that at sea level
Explanation :
The boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure surrounding the liquid. Atmospheric pressure is due to air above any given point. The atmospheric pressure at high altitudes like hill station is less than at the sea level.
[21] The information of brilliant colors in a thin soap film is a consequence of the phenomena of -
A.
Polarization and interference
B.
Diffraction and dispersion
C.
Multiple refraction and dispersion
D.
Multiple reflection and interference
Ans:
Multiple reflection and interference
Explanation :
Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.
[22] Indicate the correct arrangement for electromagnetic radiation in order of their increasing wavelength.
A.
Microwave, infrared, visible. X-rays
B.
X-rays, visible, infrared, microwave
C.
Visible, infrared, microwave, X-rays
D.
X-rays, infrared, visible, microwave
Ans:
X-rays, infrared, visible, microwave
Explanation :
The Electromagnetic spectrum in order of decreasing energy, thus increasing wavelength : Gamma Rays-wavelength: 0.01 nm ; X-rays -1 nm ; Ultra-violet Rays-0.1 micrometres ; Visible Light-Red light : 0.7 micrometres, Violet Light : 0.4 micrometres ; Infrared Radiation-0.01 mm ; Microwaves -less than 10 cm, usually lem ; Radiowaves- Long, Medium and Short Waves : 1am-10 m ; and Very High Frequency (VHF) and Ultra High Frequency (UHF): 10 m-10 cm.
[23] A black body can absorb radiations of ;
A.
lower wavelengths only
B.
intermediate wavelengths only
C.
higher wavelengths only
D.
all wavelengths
Ans:
all wavelengths
Explanation :
A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.
[24] The water from a hand pump is warm in winter because –
A.
Our body is cold in winter and the water appears to be warm
B.
The temperature inside the earth is higher than the atmospheric temperature
C.
The pumping process causes friction which warms up the water
D.
Inside water comes out and absorbs heat from the environment
Ans:
The temperature inside the earth is higher than the atmospheric temperature
Explanation :
In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
[25] When hot liquid is poured into a thick glass tumbler, it cracks because glass –
A.
is a bad conductor of heat so only inner surface expands
B.
has high temperature coefficient of expansion
C.
has a very low specific heat
D.
has low temperature coefficient of expansion
Ans:
is a bad conductor of heat so only inner surface expands
Explanation :
When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.
Explanation :
A drop of liquid assumes spherical shape because a sphere has the least surface area for a given volume.
[14] What are audible sound waves?
A.
Having frequency less than 20 Hz
B.
Having frequency between 20 Hz to 20000 Hz
C.
Having frequency more than 20000 Hz
D.
None of above
Ans:
Having frequency between 20 Hz to 20000 Hz
Explanation :
[15] Sun appears red in colour at sun-rise and sunset due to –
A.
the fact that sun emits only red colour at that time
B.
red light having longer wave length scatters away
C.
that sun Comes out of the mountains
D.
that all other colours scatter away except red
Ans:
that all other colours scatter away except red
Explanation :
According to Rayleigh's law, the intensity of scattered light varies inversely as the fourth power of its wavelength. Sunlight consists of seven colours. Of these, red has the maximum wavelength. During sun- rise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon.
[16] Why does a cannon recoil after firing?
A.
Conservation of energy
B.
Backward thrust of gases produced
C.
NeMon's third law of motion
D.
Newton's first law of motion
Ans:
NeMon's third law of motion
Explanation :
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gases (ejecta), According to Newton's third law. In case of canons, the momentum is transferred to the ground through its mount.
[17] During the motion of a projectile fired from the earth surface, .
A.
its kinetic energy remains constant
B.
its momentum remains constant
C.
vertical component of its velocity remains constant
D.
horizontal component of its velocity remains constant
Ans:
horizontal component of its velocity remains constant
Explanation :
The motion of a projectile is a two-dimensional motion—Horizontal motion and vertical motion—that take place independent of each other. The horizontal velocity of a projectile is constant (a never changing in value). The force of gravity continuously affects the vertical component, so the vertical motion is a uniformly accelerated motion.
[18] A system exhibiting S.H.M. must possess –
A.
Elasticity as well as inertia
B.
Elasticity, inertia and an external force
C.
Elasticity only
D.
Inertia only
Ans:
Elasticity as well as inertia
Explanation :
Basic conditions to execute simple harmonic motion are: (i) There must be an elastic restoring force acting on the system, (ii) the system must have inertia, and (iii) the acceleration of the system should be directly proportional to its displacement and is always directed to mean position.
[19] The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because -
A.
the ringing is not loud enough
B.
the glass of the bell jar absorbs the sound waves
C.
the bell jar is too small
D.
there is no air or any other gas in the bell jar
Ans:
there is no air or any other gas in the bell jar
Explanation :
[20] At hill stations, the boiling point of water will be –
A.
same as at sea level
B.
less than that at sea level
C.
more than that at sea level
D.
equal to the melting point of ice
Ans:
less than that at sea level
Explanation :
The boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure surrounding the liquid. Atmospheric pressure is due to air above any given point. The atmospheric pressure at high altitudes like hill station is less than at the sea level.
[21] The information of brilliant colors in a thin soap film is a consequence of the phenomena of -
A.
Polarization and interference
B.
Diffraction and dispersion
C.
Multiple refraction and dispersion
D.
Multiple reflection and interference
Ans:
Multiple reflection and interference
Explanation :
Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.
[22] Indicate the correct arrangement for electromagnetic radiation in order of their increasing wavelength.
A.
Microwave, infrared, visible. X-rays
B.
X-rays, visible, infrared, microwave
C.
Visible, infrared, microwave, X-rays
D.
X-rays, infrared, visible, microwave
Ans:
X-rays, infrared, visible, microwave
Explanation :
The Electromagnetic spectrum in order of decreasing energy, thus increasing wavelength : Gamma Rays-wavelength: 0.01 nm ; X-rays -1 nm ; Ultra-violet Rays-0.1 micrometres ; Visible Light-Red light : 0.7 micrometres, Violet Light : 0.4 micrometres ; Infrared Radiation-0.01 mm ; Microwaves -less than 10 cm, usually lem ; Radiowaves- Long, Medium and Short Waves : 1am-10 m ; and Very High Frequency (VHF) and Ultra High Frequency (UHF): 10 m-10 cm.
[23] A black body can absorb radiations of ;
A.
lower wavelengths only
B.
intermediate wavelengths only
C.
higher wavelengths only
D.
all wavelengths
Ans:
all wavelengths
Explanation :
A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.
[24] The water from a hand pump is warm in winter because –
A.
Our body is cold in winter and the water appears to be warm
B.
The temperature inside the earth is higher than the atmospheric temperature
C.
The pumping process causes friction which warms up the water
D.
Inside water comes out and absorbs heat from the environment
Ans:
The temperature inside the earth is higher than the atmospheric temperature
Explanation :
In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
[25] When hot liquid is poured into a thick glass tumbler, it cracks because glass –
A.
is a bad conductor of heat so only inner surface expands
B.
has high temperature coefficient of expansion
C.
has a very low specific heat
D.
has low temperature coefficient of expansion
Ans:
is a bad conductor of heat so only inner surface expands
Explanation :
When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.
Explanation :
According to Rayleigh's law, the intensity of scattered light varies inversely as the fourth power of its wavelength. Sunlight consists of seven colours. Of these, red has the maximum wavelength. During sun- rise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon.
[16] Why does a cannon recoil after firing?
A.
Conservation of energy
B.
Backward thrust of gases produced
C.
NeMon's third law of motion
D.
Newton's first law of motion
Ans:
NeMon's third law of motion
Explanation :
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gases (ejecta), According to Newton's third law. In case of canons, the momentum is transferred to the ground through its mount.
[17] During the motion of a projectile fired from the earth surface, .
A.
its kinetic energy remains constant
B.
its momentum remains constant
C.
vertical component of its velocity remains constant
D.
horizontal component of its velocity remains constant
Ans:
horizontal component of its velocity remains constant
Explanation :
The motion of a projectile is a two-dimensional motion—Horizontal motion and vertical motion—that take place independent of each other. The horizontal velocity of a projectile is constant (a never changing in value). The force of gravity continuously affects the vertical component, so the vertical motion is a uniformly accelerated motion.
[18] A system exhibiting S.H.M. must possess –
A.
Elasticity as well as inertia
B.
Elasticity, inertia and an external force
C.
Elasticity only
D.
Inertia only
Ans:
Elasticity as well as inertia
Explanation :
Basic conditions to execute simple harmonic motion are: (i) There must be an elastic restoring force acting on the system, (ii) the system must have inertia, and (iii) the acceleration of the system should be directly proportional to its displacement and is always directed to mean position.
[19] The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because -
A.
the ringing is not loud enough
B.
the glass of the bell jar absorbs the sound waves
C.
the bell jar is too small
D.
there is no air or any other gas in the bell jar
Ans:
there is no air or any other gas in the bell jar
Explanation :
[20] At hill stations, the boiling point of water will be –
A.
same as at sea level
B.
less than that at sea level
C.
more than that at sea level
D.
equal to the melting point of ice
Ans:
less than that at sea level
Explanation :
The boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure surrounding the liquid. Atmospheric pressure is due to air above any given point. The atmospheric pressure at high altitudes like hill station is less than at the sea level.
[21] The information of brilliant colors in a thin soap film is a consequence of the phenomena of -
A.
Polarization and interference
B.
Diffraction and dispersion
C.
Multiple refraction and dispersion
D.
Multiple reflection and interference
Ans:
Multiple reflection and interference
Explanation :
Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.
[22] Indicate the correct arrangement for electromagnetic radiation in order of their increasing wavelength.
A.
Microwave, infrared, visible. X-rays
B.
X-rays, visible, infrared, microwave
C.
Visible, infrared, microwave, X-rays
D.
X-rays, infrared, visible, microwave
Ans:
X-rays, infrared, visible, microwave
Explanation :
The Electromagnetic spectrum in order of decreasing energy, thus increasing wavelength : Gamma Rays-wavelength: 0.01 nm ; X-rays -1 nm ; Ultra-violet Rays-0.1 micrometres ; Visible Light-Red light : 0.7 micrometres, Violet Light : 0.4 micrometres ; Infrared Radiation-0.01 mm ; Microwaves -less than 10 cm, usually lem ; Radiowaves- Long, Medium and Short Waves : 1am-10 m ; and Very High Frequency (VHF) and Ultra High Frequency (UHF): 10 m-10 cm.
[23] A black body can absorb radiations of ;
A.
lower wavelengths only
B.
intermediate wavelengths only
C.
higher wavelengths only
D.
all wavelengths
Ans:
all wavelengths
Explanation :
A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.
[24] The water from a hand pump is warm in winter because –
A.
Our body is cold in winter and the water appears to be warm
B.
The temperature inside the earth is higher than the atmospheric temperature
C.
The pumping process causes friction which warms up the water
D.
Inside water comes out and absorbs heat from the environment
Ans:
The temperature inside the earth is higher than the atmospheric temperature
Explanation :
In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
[25] When hot liquid is poured into a thick glass tumbler, it cracks because glass –
A.
is a bad conductor of heat so only inner surface expands
B.
has high temperature coefficient of expansion
C.
has a very low specific heat
D.
has low temperature coefficient of expansion
Ans:
is a bad conductor of heat so only inner surface expands
Explanation :
When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.
Explanation :
The motion of a projectile is a two-dimensional motion—Horizontal motion and vertical motion—that take place independent of each other. The horizontal velocity of a projectile is constant (a never changing in value). The force of gravity continuously affects the vertical component, so the vertical motion is a uniformly accelerated motion.
[18] A system exhibiting S.H.M. must possess –
A.
Elasticity as well as inertia
B.
Elasticity, inertia and an external force
C.
Elasticity only
D.
Inertia only
Ans:
Elasticity as well as inertia
Explanation :
Basic conditions to execute simple harmonic motion are: (i) There must be an elastic restoring force acting on the system, (ii) the system must have inertia, and (iii) the acceleration of the system should be directly proportional to its displacement and is always directed to mean position.
[19] The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because -
A.
the ringing is not loud enough
B.
the glass of the bell jar absorbs the sound waves
C.
the bell jar is too small
D.
there is no air or any other gas in the bell jar
Ans:
there is no air or any other gas in the bell jar
Explanation :
[20] At hill stations, the boiling point of water will be –
A.
same as at sea level
B.
less than that at sea level
C.
more than that at sea level
D.
equal to the melting point of ice
Ans:
less than that at sea level
Explanation :
The boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure surrounding the liquid. Atmospheric pressure is due to air above any given point. The atmospheric pressure at high altitudes like hill station is less than at the sea level.
[21] The information of brilliant colors in a thin soap film is a consequence of the phenomena of -
A.
Polarization and interference
B.
Diffraction and dispersion
C.
Multiple refraction and dispersion
D.
Multiple reflection and interference
Ans:
Multiple reflection and interference
Explanation :
Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.
[22] Indicate the correct arrangement for electromagnetic radiation in order of their increasing wavelength.
A.
Microwave, infrared, visible. X-rays
B.
X-rays, visible, infrared, microwave
C.
Visible, infrared, microwave, X-rays
D.
X-rays, infrared, visible, microwave
Ans:
X-rays, infrared, visible, microwave
Explanation :
The Electromagnetic spectrum in order of decreasing energy, thus increasing wavelength : Gamma Rays-wavelength: 0.01 nm ; X-rays -1 nm ; Ultra-violet Rays-0.1 micrometres ; Visible Light-Red light : 0.7 micrometres, Violet Light : 0.4 micrometres ; Infrared Radiation-0.01 mm ; Microwaves -less than 10 cm, usually lem ; Radiowaves- Long, Medium and Short Waves : 1am-10 m ; and Very High Frequency (VHF) and Ultra High Frequency (UHF): 10 m-10 cm.
[23] A black body can absorb radiations of ;
A.
lower wavelengths only
B.
intermediate wavelengths only
C.
higher wavelengths only
D.
all wavelengths
Ans:
all wavelengths
Explanation :
A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.
[24] The water from a hand pump is warm in winter because –
A.
Our body is cold in winter and the water appears to be warm
B.
The temperature inside the earth is higher than the atmospheric temperature
C.
The pumping process causes friction which warms up the water
D.
Inside water comes out and absorbs heat from the environment
Ans:
The temperature inside the earth is higher than the atmospheric temperature
Explanation :
In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
[25] When hot liquid is poured into a thick glass tumbler, it cracks because glass –
A.
is a bad conductor of heat so only inner surface expands
B.
has high temperature coefficient of expansion
C.
has a very low specific heat
D.
has low temperature coefficient of expansion
Ans:
is a bad conductor of heat so only inner surface expands
Explanation :
When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.
Explanation :
[20] At hill stations, the boiling point of water will be –
A.
same as at sea level
B.
less than that at sea level
C.
more than that at sea level
D.
equal to the melting point of ice
Ans:
less than that at sea level
Explanation :
The boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure surrounding the liquid. Atmospheric pressure is due to air above any given point. The atmospheric pressure at high altitudes like hill station is less than at the sea level.
[21] The information of brilliant colors in a thin soap film is a consequence of the phenomena of -
A.
Polarization and interference
B.
Diffraction and dispersion
C.
Multiple refraction and dispersion
D.
Multiple reflection and interference
Ans:
Multiple reflection and interference
Explanation :
Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.
[22] Indicate the correct arrangement for electromagnetic radiation in order of their increasing wavelength.
A.
Microwave, infrared, visible. X-rays
B.
X-rays, visible, infrared, microwave
C.
Visible, infrared, microwave, X-rays
D.
X-rays, infrared, visible, microwave
Ans:
X-rays, infrared, visible, microwave
Explanation :
The Electromagnetic spectrum in order of decreasing energy, thus increasing wavelength : Gamma Rays-wavelength: 0.01 nm ; X-rays -1 nm ; Ultra-violet Rays-0.1 micrometres ; Visible Light-Red light : 0.7 micrometres, Violet Light : 0.4 micrometres ; Infrared Radiation-0.01 mm ; Microwaves -less than 10 cm, usually lem ; Radiowaves- Long, Medium and Short Waves : 1am-10 m ; and Very High Frequency (VHF) and Ultra High Frequency (UHF): 10 m-10 cm.
[23] A black body can absorb radiations of ;
A.
lower wavelengths only
B.
intermediate wavelengths only
C.
higher wavelengths only
D.
all wavelengths
Ans:
all wavelengths
Explanation :
A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.
[24] The water from a hand pump is warm in winter because –
A.
Our body is cold in winter and the water appears to be warm
B.
The temperature inside the earth is higher than the atmospheric temperature
C.
The pumping process causes friction which warms up the water
D.
Inside water comes out and absorbs heat from the environment
Ans:
The temperature inside the earth is higher than the atmospheric temperature
Explanation :
In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
[25] When hot liquid is poured into a thick glass tumbler, it cracks because glass –
A.
is a bad conductor of heat so only inner surface expands
B.
has high temperature coefficient of expansion
C.
has a very low specific heat
D.
has low temperature coefficient of expansion
Ans:
is a bad conductor of heat so only inner surface expands
Explanation :
When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.
Explanation :
Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.
[22] Indicate the correct arrangement for electromagnetic radiation in order of their increasing wavelength.
A.
Microwave, infrared, visible. X-rays
B.
X-rays, visible, infrared, microwave
C.
Visible, infrared, microwave, X-rays
D.
X-rays, infrared, visible, microwave
Ans:
X-rays, infrared, visible, microwave
Explanation :
The Electromagnetic spectrum in order of decreasing energy, thus increasing wavelength : Gamma Rays-wavelength: 0.01 nm ; X-rays -1 nm ; Ultra-violet Rays-0.1 micrometres ; Visible Light-Red light : 0.7 micrometres, Violet Light : 0.4 micrometres ; Infrared Radiation-0.01 mm ; Microwaves -less than 10 cm, usually lem ; Radiowaves- Long, Medium and Short Waves : 1am-10 m ; and Very High Frequency (VHF) and Ultra High Frequency (UHF): 10 m-10 cm.
[23] A black body can absorb radiations of ;
A.
lower wavelengths only
B.
intermediate wavelengths only
C.
higher wavelengths only
D.
all wavelengths
Ans:
all wavelengths
Explanation :
A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.
[24] The water from a hand pump is warm in winter because –
A.
Our body is cold in winter and the water appears to be warm
B.
The temperature inside the earth is higher than the atmospheric temperature
C.
The pumping process causes friction which warms up the water
D.
Inside water comes out and absorbs heat from the environment
Ans:
The temperature inside the earth is higher than the atmospheric temperature
Explanation :
In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
[25] When hot liquid is poured into a thick glass tumbler, it cracks because glass –
A.
is a bad conductor of heat so only inner surface expands
B.
has high temperature coefficient of expansion
C.
has a very low specific heat
D.
has low temperature coefficient of expansion
Ans:
is a bad conductor of heat so only inner surface expands
Explanation :
When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.
Explanation :
A black body is a theoretical object that absorbs 100% of the radiation that hits it. Therefore it reflects no radiation and appears perfectly black. At a particular temperature the black body would emit the maximum amount of energy possible for that temperature. This value is known as the black body radiation. It would emit at every wavelength of light as it must be able to absorb every wavelength to be sure of absorbing all incoming radiation.
[24] The water from a hand pump is warm in winter because –
A.
Our body is cold in winter and the water appears to be warm
B.
The temperature inside the earth is higher than the atmospheric temperature
C.
The pumping process causes friction which warms up the water
D.
Inside water comes out and absorbs heat from the environment
Ans:
The temperature inside the earth is higher than the atmospheric temperature
Explanation :
In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.
[25] When hot liquid is poured into a thick glass tumbler, it cracks because glass –
A.
is a bad conductor of heat so only inner surface expands
B.
has high temperature coefficient of expansion
C.
has a very low specific heat
D.
has low temperature coefficient of expansion
Ans:
is a bad conductor of heat so only inner surface expands
Explanation :
When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.
Explanation :
When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.