Laws Of Thermodynamics Quiz: Can You Explain Them?

Question 1

In an isothermal process, there is no change in

Accepted Answer

temperature.

Answer

pressure.

Answer

volume.

Answer

heat.

Question 2

A gas is expanded to twice its original volume with no change in its temperature. This process is

Accepted Answer

isothermal.

Answer

isochoric.

Answer

isobaric.

Answer

adiabatic.

Question 3

In an isochoric process, there is no change in

Accepted Answer

volume.

Answer

pressure.

Answer

temperature.

Answer

internal energy.

Question 4

In an isobaric process, there is no change in

Accepted Answer

pressure.

Answer

temperature.

Answer

volume.

Answer

internal energy.

Question 5

A heat engine absorbs 64 kcal of heat each cycle and exhausts 42 kcal. Calculate the work done each cycle.

Accepted Answer

22 kcal

Answer

42 kcal

Answer

64 kcal

Answer

106 kcal

Question 6

A refrigerator removes heat from the freezing compartment at the rate of 20 kJ and ejects 24 kJ into a room per cycle. How much work is required in each cycle?

Accepted Answer

4 kJ

Answer

20 kJ

Answer

24 kJ

Answer

44 kJ

Question 7

Is it possible to transfer heat from a hot reservoir to a cold reservoir?

Accepted Answer

Yes; this will happen naturally.

Answer

No.

Answer

Yes, but work will have to be done.

Answer

Theoretically yes, but it hasn't been accomplished yet.

Question 8

When water freezes, the entropy of the water

Accepted Answer

decreases.

Answer

increases.

Answer

does not change.

Answer

could either increase or decrease; it depends on other factors.

Question 9

A heat engine has an efficiency of 35.0% and receives 150 J of heat per cycle. How much work does it perform in each cycle?

Accepted Answer

52.5 J

Answer

zero

Answer

97.5 J

Answer

150 J

Question 10

During an isothermal process, 5.0 J of heat is removed from an ideal gas. What is the change in internal energy?

Accepted Answer

zero

Answer

2.5 J

Answer

5.0 J

Answer

10 J

Question 11

If the theoretical efficiency of a Carnot engine is to be 100%, the heat sink must be

Accepted Answer

at absolute zero.

Answer

at 0°C.

Answer

at 100°C.

Answer

infinitely hot.

Question 12

A Carnot cycle consists of

Accepted Answer

two adiabats and two isotherms.

Answer

two adiabats and two isobars.

Answer

two isobars and two isotherms.

Answer

two isotherms and two isomets.

Question 13

When the first law of thermodynamics, Q = &Delta;U + W, is applied to an ideal gas that is taken through an isothermal process,

Accepted Answer

ΔU = 0

Answer

W = 0

Answer

Q = 0

Answer

none of the above

Question 14

During each cycle of operation, a refrigerator absorbs 230 J of heat from the freezer and expels 356 J of heat to the room. How much work input is required in each cycle?

Accepted Answer

126 J

Answer

712 J

Answer

586 J

Answer

460 J

Question 15

When the first law of thermodynamics, Q = &Delta;U + W, is applied to an ideal gas that is taken through an adiabatic process,

Accepted Answer

Q = 0.

Answer

ΔU = 0.

Answer

W = 0.

Answer

none of the above

Question 16

200 J of work is done in compressing a gas adiabatically. What is the change in internal energy of the gas?

Accepted Answer

200 J

Answer

zero

Answer

100 J

Answer

There is not enough information to determine.

Question 17

When the first law of thermodynamics, Q = &Delta;U + W, is applied to an ideal gas that is taken through an isochoric process,

Accepted Answer

W = 0.

Answer

ΔU = 0.

Answer

Q = 0.

Answer

none of the above

Question 18

An ideal gas is compressed to one-half its original volume during an isothermal process. The final pressure of the gas

Accepted Answer

increases to twice its original value.

Answer

increases to less than twice its original value.

Answer

increases to more than twice its original value.

Answer

does not change.

Question 19

Is it possible to transfer heat from a cold reservoir to a hot reservoir?

Accepted Answer

Yes, but work will have to be done.

Answer

No.

Answer

Yes; this will happen naturally.

Answer

Theoretically yes, but it hasn't been accomplished yet.

Question 20

The second law of thermodynamics leads us to conclude that

Accepted Answer

disorder in the universe is increasing with the passage of time.

Answer

the total energy of the universe is constant.

Answer

it is theoretically possible to convert heat into work with 100% efficiency.

Answer

the average temperature of the universe is increasing with the passage of time.

Question 21

In an isochoric process, the internal energy of a system decreases by 50 J. What is the heat exchange?

Accepted Answer

-50 J

Answer

zero

Answer

50 J

Answer

none of the above

Question 22

A system consists of 3.0 kg of water at 80&deg;C. 30 J of work is done on the system by stirring with a paddle wheel, while 66 J of heat is removed. What is the change in internal energy of the system?

Accepted Answer

-36 J

Answer

36 J

Answer

96 J

Answer

-96 J

Question 23

A heat engine receives 7000 J of heat and loses 3000 J in each cycle. What is the efficiency?

Accepted Answer

57%

Answer

30%

Answer

70%

Answer

43%

Question 24

A heat engine absorbs 64 kcal of heat each cycle and exhausts 42 kcal. Calculate the efficiency of each cycle.

Accepted Answer

34%

Answer

66%

Answer

50%

Answer

150%

Question 25

An ideal gas is compressed isothermally from 30 L to 20 L. During this process, 6.0 J of energy is expended by the external mechanism that compressed the gas. What is the change of internal energy for this gas?

Accepted Answer

zero

Answer

6.0 J

Answer

-6.0 J

Answer

none of the above

Laws Of Thermodynamics Quiz: Can You Explain Them? Live Quiz