Physics Quiz

What is the term for the ability of a thermodynamic system to exchange energy with its surroundings?

• Thermal equilibrium

• Thermodynamic process

• Mechanical equilibrium

• Chemical equilibrium

What happens to the system when T_S = T_E?

• The system gains energy

• The system loses energy

• No net transfer of energy occurs

• The system becomes unstable

When is a system said to be in mechanical equilibrium?

• When there are no unbalanced forces within the system and surroundings

• When the temperature is uniform throughout the system

• When there are no chemical reactions going on within the system

• When the pressure is different throughout the system

What is an isobaric process?

• A process at constant pressure.

• A process at constant volume.

• A process at constant temperature.

• A process at constant entropy.

What is the primary use of heat in an isochoric process?

• To increase the internal energy of the system.

• To do work on the surroundings.

• To change the volume of the system.

• To change the pressure of the system.

What is the equation for the change in internal energy in an adiabatic process?

• ΔU = Cv (ΔT)

• ΔU = Cp (ΔT)

• ΔU = R (ΔT)

• ΔU = T (ΔT)

What is the role of the hot reservoir in a heat engine?

• It absorbs heat from the working substance at a lower temperature.

• It absorbs heat from the working substance at a higher temperature.

• It converts heat into work.

• It rejects heat to the cold reservoir.

What is the fundamental limit on the efficiency of a heat engine set by?

• The first law of thermodynamics

• The second law of thermodynamics

• The third law of thermodynamics

• The zeroth law of thermodynamics

What is the equation for the thermal efficiency of a heat engine using QH and QC?

• η = 1 - QC / QH

• η = 1 + QC / QH

• η = QH / QC

• η = QC / QH

What is the main difference between refrigerators and heat pumps compared to heat engines?

• They work in the same direction as heat engines.

• They convert heat into mechanical work.

• They work in the backward direction, converting mechanical work into heat.

• They do not involve any phase change of the refrigerant.