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# Physics Test 10 - Heat And Thermodynamics

## 30 Questions MCQ Test JEE Main Mock Test Series 2020 & Previous Year Papers | Physics Test 10 - Heat And Thermodynamics

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This mock test of Physics Test 10 - Heat And Thermodynamics for JEE helps you for every JEE entrance exam. This contains 30 Multiple Choice Questions for JEE Physics Test 10 - Heat And Thermodynamics (mcq) to study with solutions a complete question bank. The solved questions answers in this Physics Test 10 - Heat And Thermodynamics quiz give you a good mix of easy questions and tough questions. JEE students definitely take this Physics Test 10 - Heat And Thermodynamics exercise for a better result in the exam. You can find other Physics Test 10 - Heat And Thermodynamics extra questions, long questions & short questions for JEE on EduRev as well by searching above.
QUESTION: 1

### For Boyle’s law to hold good, the gas should be

Solution: For Boyle's law gases must obey ideal gas equation
PV=nRT
Boyles law states that for a fixed amount of gas at constant temperature pressure is inversely proportional to its volume.i.e.PV=constant
QUESTION: 2

### A bulb contains 1 mole of hydrogen and 1 mole of oxygen at temperature T. The ratio of rms values of velocity of hydrogen molecules to that of oxygen molecule is

Solution: RMS speed sqroot of 3RT/M M=molar mass T=temp R=cont used it
QUESTION: 3

### An ideal gas is heated from 270 to 6270 C at constant pressure. If initial volume was 4m3,then the final volume of gas will be

Solution:
QUESTION: 4

Critical temperature can be difined as the temperature

Solution:
QUESTION: 5

A molecule of mass m of an ideal gas collides with the wall of the vessel with the same velocity. The change in the linear momentum of the molecule will be

Solution:
Change in linear momentum = Final
Momentum-Initial momentum.
Momentum = mass x velocity
Initial velocity = v
Since molecule returns back with same velocity, final velocity = -v
Initial momentum = mv
Final momentum = -mv
Change in linear momentum is = -mv-(mv)=-2mv
QUESTION: 6

Rate of diffusion is

Solution:
QUESTION: 7

Which one of the following is not a thermodynamical co-ordinate ?

Solution:
QUESTION: 8

The mean kinetic energy of a molecule of a gas at 300 K is 6.21 x 10-21 The root mean square velocity of a molecule of H2 gas at this temperature will be(R=8.3 J/mole K,N= 6.02 x 1023 /mole, mass of the
hydrogen moleucle = 2 x 1.67 x 10-27 Kg)

Solution:
QUESTION: 9

At what temperautre will the rms velocity of oxygen moleucle be sufficient, so as to escape from the earth ? Escape velocity from the earth is 11.0 km/s and the mass of 1 moleucle of oxygen 5.34 x 10-26 (Boltzman constant k =1.38 x 10-23 J/K)

Solution:
QUESTION: 10

The temperature of inside and outside of a refrigerator are 273 K and 303 K respectively.  Assuming that the regrigerator cycle is reverisble,for every joule of work done, the heat delivered to the surrounding will be nearly

Solution: QUESTION: 11

A sample of gas expands from volume V1 to V2. The amount of work done by the gas is greatest, when the expansion is

Solution: While expanding the PV diagram shows drop in pressure for isothermal and even more in adiabatic process, but in isobaric process pressure remains constant ie parallel to V axis. the work done in P V diagram is area under PV curve between the limits of volumes. hence the area is maximum for isobaric then comes isothermal and adiabatic has the least work done for a given range of volumes.
QUESTION: 12

During the adiabatic expansion of 2 moles of a gas the internal energy of a gas is found to decrease by 2 J. The work done during the process on gas will be equal to

Solution: In any adiabatic process heat is not given or taken out of system , so there will be adiabatic expansion it will be on expense of its own internal energy so we see decrease in internal energy by first law of thermodynamics that when heat is given to a system it either is used in doing work or increasing internal energy,  when no heat is given and system is expanding it has to spend it's own internal energy appearing as work done.
QUESTION: 13

Magnitude of slope of an adiabatic curve is always

Solution:
QUESTION: 14

Air is filled in a bottle at atmoshperic pressure and it is cordked at 350C. If the cork can come out at 3 atmospheric pressure then upto what temperature should the bottle be heated in order to remove the cork?

Solution:
P1 V1 / T1 = P2 V2 / T2
Volume is constant (bottle volume). So,
P1 / T1 = P2 / T2
1 / (273+35) = 3 / T2
So temperature to be heated is,
651 C.
At which bottle would have vaporized.
QUESTION: 15

A perfect gas goes from state A to another state B by absorbing  8 x 105 J of heat and doing 6.5 x 105 J  of expernal work. It is now transfered between the same two states in another process in which it absorbs 105 J of heat. Then, in the second process

Solution: Now ΔQ=ΔW +ΔE

For first case, 8 x 10'5=6.5 x 10'5+ΔE

Therefore, ΔE=1.5 x 10'5 J

In the second case, ΔQ=10'5 J

Therefore ΔW=ΔQ-ΔE

=-0.5 x 10'5 so answer option A correct
QUESTION: 16

If 150 J of heat is added to a system and the work done by the system is 110 J. Then, change in internal energy will be

Solution:
QUESTION: 17

An ideal refirgator has a freezer at a temperature of -130C. The coefficient of performance of the engine is 5. The temperature of the air (to which heat is rejected) will be

Solution:
QUESTION: 18

A Carnot reversible engine converts 1/6 of heat input work. When the temperature of the sink is reduced by 62 K, the efficiency of Carnot’s cycle becomes 1/3. The temperature of the source and sink will be

Solution:
QUESTION: 19

When a solid is converted into a gas,directly by heating then this process is known as

Solution:
QUESTION: 20

The latent heat of vapourization of water is 2240 J.If the work done in the process of vapourization of 1 g is 168 J, then increase in internal energy will be

Solution:
QUESTION: 21

If the temperature of a black body increases from 70C to 2870C then, the rate of energy of radiation is

Solution: QUESTION: 22

Woolen clothes keep the body warm because the woll

Solution: The reason why wool keeps us warm is due to the air pockets between fibers of wool. The air around us is a not a good conductor of heat. If we could keep the air around us still then it would act like a bad conductor of heat. The fibers of wool prevent the movement of air in the air pockets, keeping it still.
QUESTION: 23

Heat travels through vaccum by

Solution: Heat moves in three ways: Radiation, conduction, and convection. Radiation happens when heat moves as energy waves, called infrared waves, directly from its source to something else. This is how the heat from the Sun gets to Earth. In fact, all hot things radiate heat to cooler things.
QUESTION: 24

The sun emits a light with maximum wavelength 510 nm while another star emits a light with maximum wavelength of 350 nm. The ratio of surface temperature of sun and the star will be

Solution:
QUESTION: 25

Direction : Read the following question and choose
A. If both Assetion and Reason are correct and reason is the correct exaplanation of assertion
B. If both Assertion and Reason are true, but Reason is not correct explanation of the Assertion
C. If Assertion is true, but the Reason is false
D. If Assertion is false, but the Reason is true
E. If both assertion and reason are false
Assertion : A body that is a good ratiator is also a good absorber of radiation at a given wavelength
Reason : According to Kirchhoff’s law the absorptivity of a body is equal to its emissivity at a given wavelength

Solution:
QUESTION: 26

Direction : Read the following question and choose
A. If both Assetion and Reason are correct and reason is the correct exaplanation of assertion
B. If both Assertion and Reason are true, but Reason is not correct explanation of the Assertion
C. If Assertion is true, but the Reason is false
D. If Assertion is false, but the Reason is true
E. If both assertion and reason are false
Assertion : Temperatures near the sea coast are moderate.
Reason : Water has a high thermal conductivity

Solution: Temperature variations between coastal areas and sea water, causing cold breeze at day .
QUESTION: 27

Direction : Read the following question and choose
A. If both Assetion and Reason are correct and reason is the correct exaplanation of assertion
B. If both Assertion and Reason are true, but Reason is not correct explanation of the Assertion
C. If Assertion is true, but the Reason is false
D. If Assertion is false, but the Reason is true
E. If both assertion and reason are false
Assertion : It is hotter over the top of a fire than at the same distance on the sides
Reason : Air surrounding the fire conducts more heat upward

Solution: Hot air move upward due to low pressure and cold Air Move downward.
QUESTION: 28

Direction : Read the following question and choose
A. If both Assetion and Reason are correct and reason is the correct exaplanation of assertion
B. If both Assertion and Reason are true, but Reason is not correct explanation of the Assertion
C. If Assertion is true, but the Reason is false
D. If Assertion is false, but the Reason is true
E. If both assertion and reason are false
Assertion : If an ideal gas expands in vaccum in an inuslated chamber  ΔQ, ΔU and ΔW all are zero
Reason : Temperature of the gas remains constant

Solution: In vacuum there is no opposition for the expansion.So no work is done in this process.Also when free expansion of gas takes place in thermally insulated container tem remains same
the reason for no work done is not mentioned so it's not a correct explanation.
QUESTION: 29

Direction : Read the following question and choose
A. If both Assetion and Reason are correct and reason is the correct exaplanation of assertion
B. If both Assertion and Reason are true, but Reason is not correct explanation of the Assertion
C. If Assertion is true, but the Reason is false
D. If Assertion is false, but the Reason is true
E. If both assertion and reason are false
Assertion : Specific heat of a body is always greater than its thermal capacity
Reason : Thermal capacity is the heat required for raising temperature of unit mass of the body through unit degree

Solution:
QUESTION: 30

Direction : Read the following question and choose
A. If both Assetion and Reason are correct and reason is the correct exaplanation of assertion
B. If both Assertion and Reason are true, but Reason is not correct explanation of the Assertion
C. If Assertion is true, but the Reason is false
D. If Assertion is false, but the Reason is true
E. If both assertion and reason are false
Assertion : The molecules at 00C ice and water will have same potential energy
Reason : Potential energy depends only on temperature of the system

Solution: