FY Sem-2 Physics Major S1

What is the entropy change during an isothermal expansion process?

• It is negative.

• It is zero.

• It is positive.

• It is undefined.

According to the second law of thermodynamics, entropy in a closed system can:

• Only increase.

• Always increase.

• Always decrease.

• Remain constant or increase.

What happens to the entropy of the gas during a reversible compression?

• It remains constant.

• It becomes negative.

• It decreases.

• It increases.

In a Carnot engine, heat is absorbed from a reservoir at which temperature?

• 0 K

• T_H

• T_L

• Room temperature

What type of processes connect the two isotherms in a Carnot cycle?

• Isothermal processes.

• Adiabatic processes.

• Irreversible processes.

• Constant pressure processes.

What is the efficiency of a Carnot engine dependent on?

• The volume of the gas.

• The temperatures of the reservoirs.

• The nature of the working substance.

• The pressure of the gas.

During which process does the working substance do positive work?

• Isothermal compression.

• Isothermal expansion.

• Adiabatic compression.

• Adiabatic expansion.

What is the relationship between heat transfer and entropy change?

• Q = 0 implies ΔS = 0.

• Q > 0 implies ΔS < 0.

• Q < 0 implies ΔS > 0.

• Q > 0 implies ΔS > 0.

What does the area under the curve in a pV diagram represent?

• Heat absorbed.

• Entropy change.

• Work done.

• Change in internal energy.

What is the result of a decrease in entropy in part of a closed system?

• The total entropy must also decrease.

• The total entropy remains constant.

• There must be an equal increase in another part.

• Entropy can only decrease.