Which law of thermodynamics says that the efficiency of a heat engine cannot be 1?

• First

• Zeroth

• Second

• Third

2. Which of the following is the Kelvin-Planck statement?

• Heat from a cold reservoir cannot be transferred to a hot reservoir without external work.

• Efficiency for a reversible cyclic process can be 1.

• The heat from a hot reservoir can be converted entirely into work if reversible.

• The efficiency of a heat engine is less than 1.

The second law of thermodynamics states that

• The entropy of an isolated system can never decrease over time.

• The entropy of a pure crystalline substance at 0K is 0.

• Energy is conserved

• The entropy of a system can never decrease

What is its efficiency if an engine takes 5 J of heat energy from a reservoir and rejects 3 J to the surroundings?

• 2/5

• 3/5

• 1/5

• 0

What is the coefficient of performance of a refrigerator? Let Q₁ be the heat released to the hot reservoir, Q₂ be the heat extracted from a cold reservoir, and W be the work done on the refrigerator.

• Q₁/W

• Q₁/Q₂

• Q₂/W

• Q₂/Q₁

Select the correct order of steps a working substance (gas) goes through in a refrigerator.

• Expansion of gas, absorption of heat, heating of vapour, release of heat

• Absorption of heat, expansion of gas, heating of vapour, release of heat

• Heating of vapour, expansion of gas, absorption of heat, release of heat

• Heating of vapour, absorption of heat, expansion of gas, release of heat

What is the correct order of steps for a Carnot cycle?

• Isothermal expansion, adiabatic expansion, isothermal compression, adiabatic compression

• Isothermal compression, adiabatic expansion, isothermal expansion, adiabatic compression

• Adiabatic compression, adiabatic expansion, isothermal expansion, isothermal compression

• Adiabatic compression, isothermal expansion, adiabatic expansion, and isothermal compression

Carnot engine follows ____________

• Isothermal process

• Isoentropic process

• Isothermal and Isoentropic process

• None of the mentioned

Clausius inequality is applied at ____________.

• reversible isothermal heat addition

• reversible adiabatic expansion

• reversible isothermal compression

• reversible isothermal heat rejection

The working fluid of the Rankine cycle is usually

• Water

• Methane

• Hard water

• None of the mentioned