Physics 11th Chap 8 : Topic 15 - Maryam Publications

Physics Chapter 8 : Topic 15

Second Law of Thermodynamics

1 / 30

The second law of thermodynamics mainly explains:

A) Relationship between force and displacement

B) Direction of energy transfer and limitations of energy conversion

C) Conservation of energy

D) Conservation of mass

2 / 30

Which statement correctly represents the second law of thermodynamics?

A) Heat naturally flows from hot objects to cold objects.

B) Energy can be created from nothing.

C) All heat can be converted into useful work.

D) Heat naturally flows from cold objects to hot objects.

3 / 30

According to the second law, a heat engine cannot have an efficiency of:

A) $\mathbf{75\%}$

B) $\mathbf{100\%}$

C) $\mathbf{50\%}$

D) $\mathbf{25\%}$

4 / 30

The second law of thermodynamics places a limitation on:

A) Energy conservation

B) Momentum conservation

C) Mass conservation

D) Heat engine efficiency

5 / 30

Which of the following processes is impossible according to the second law?

A) Heat flowing naturally from a cold object to a hot object

B) Heat flowing from a hot object to a cold object

C) Expansion of a gas

D) Conversion of some heat into work

6 / 30

The second law of thermodynamics introduces the concept of:

A) Momentum

B) Acceleration

C) Entropy

D) Force

7 / 30

Entropy of an isolated system:

A) Always remains zero

B) Always decreases

C) Never decreases

D) Is converted into energy

8 / 30

A natural process occurs in the direction of:

A) Increasing total entropy

B) Decreasing total entropy

C) Zero energy transfer

D) Increasing temperature only

9 / 30

Which statement is known as the Clausius statement of the second law?

A) Energy cannot be conserved.

B) Heat cannot flow from a cold body to a hot body without external work.

C) Work cannot be converted into heat.

D) Heat cannot flow from a hot body to a cold body.

10 / 30

Which statement is known as the Kelvin-Planck statement?

A) No heat engine can convert all absorbed heat into work.

B) Work cannot produce heat.

C) Energy cannot be transferred.

D) Heat cannot exist in a system.

11 / 30

A heat engine operates between:

A) Two cold reservoirs

B) A hot reservoir and a cold reservoir

C) Two reservoirs of equal temperature

D) A vacuum and a reservoir

12 / 30

The efficiency of a heat engine is always less than $\mathbf{100\%}$ because:

A) Energy is destroyed.

B) Heat has no energy.

C) Work cannot be produced.

D) Some heat is rejected to the cold reservoir.

13 / 30

A heat engine receives $\mathbf{100}\mathbf{0\ J}$ heat and rejects $\mathbf{400\ J}$. The work output is:

A) $\mathbf{1400\ J}$

B) $\mathbf{1000\ J}$

C) $\mathbf{600\ J}$

D) $\mathbf{400\ J}$

14 / 30

Increasing the temperature difference between hot and cold reservoirs:

A) Decreases possible efficiency

B) Makes efficiency zero

C) Stops heat transfer

D) Increases possible efficiency

15 / 30

A heat engine operating between reservoirs of the same temperature:

A) Has maximum efficiency

B) Converts all heat into work

C) Cannot produce continuous work

D) Produces infinite energy

16 / 30

A machine that converts all absorbed heat into work would violate:

A) Newton’s laws

B) Boyle’s law

C) Second law of thermodynamics

D) First law of thermodynamics

17 / 30

A perpetual motion machine of the second kind is impossible because:

A) It requires no energy.

B) It violates conservation of mass.

C) It violates the second law of thermodynamics.

D) It has no moving parts.

18 / 30

A refrigerator transfers heat:

A) From hot region to cold region naturally

B) Without energy input

C) By destroying heat

D) From cold region to hot region using work input

19 / 30

A refrigerator does not violate the second law because:

A) It uses external energy to transfer heat from cold to hot.

B) It creates energy.

C) It reduces total entropy of the universe.

D) It does not transfer heat.

20 / 30

The direction of natural heat flow is:

A) Hot to cold

B) Cold to hot

C) Vacuum to gas

D) Low pressure to high pressure

21 / 30

Entropy is a measure of:

A) Temperature only

B) Disorder or randomness of a system

C) Pressure only

D) Total mass

22 / 30

Which process increases entropy?

A) Returning to original state without effects

B) Maintaining equilibrium

C) Perfect reversible compression

D) Mixing of gases

23 / 30

A reversible process has:

A) Zero entropy production

B) Infinite entropy production

C) Negative entropy production

D) Maximum entropy production

24 / 30

An irreversible process causes:

A) Increase in entropy of universe

B) Decrease in entropy of universe

C) No change in entropy

D) Complete energy loss

25 / 30

Cooling of hot tea in a room is an example of:

A) Irreversible process

B) Isolated process

C) Reversible process

D) Cyclic process

26 / 30

Friction makes a process irreversible because:

A) It destroys energy.

B) It converts useful mechanical energy into random thermal energy.

C) It stops particle motion.

D) It creates energy.

27 / 30

Burning of fuel is irreversible because:

A) It decreases entropy.

B) It produces heat and increases disorder.

C) It can easily occur backward.

D) No energy conversion occurs.

28 / 30

The first law and second law differ because:

A) Second law rejects energy conservation.

B) Both laws explain identical concepts.

C) First law applies only to gases.

D) First law explains energy conservation, second law explains direction of processes.

29 / 30

Which statement best explains why useful energy decreases in real processes?

A) Energy is destroyed.

B) Energy becomes more dispersed and less available for work.

C) Temperature always becomes zero.

D) Mass disappears.

30 / 30

The main conclusion of the second law of thermodynamics is:

A) Heat can always be converted completely into work.

B) Energy cannot change form.

C) All processes are reversible.

D) Energy transformations have natural directions and limitations.

Your score is

0%