JEE Physics - MCQ Practice Questions

For a reversible isothermal process of an ideal gas, the entropy change of the universe is:

A gas undergoes a process where PV² = constant. If the gas expands from volume V to 2V, what is the ratio of final to initial pressure?

A thermally insulated container holds 2 moles of oxygen gas at 300 K. A heating element supplies 5000 J of heat to the gas. What is the final temperature? (C_v for O₂ = 5R/2, R = 8.314 J/mol·K)

For a Carnot refrigerator operating between 250 K (cold reservoir) and 300 K (hot reservoir), the coefficient of performance (COP) is:

A substance has a latent heat of vaporization of 2260 kJ/kg at 373 K. The entropy change during vaporization of 1 kg of water is approximately:

When a system undergoes a process where both Q and W are positive, which statement is true?

A system undergoes a cyclic process. The internal energy change over one complete cycle is ΔU. Which statement is correct?

Two identical blocks at different temperatures are brought into thermal contact in an isolated system. Block A at 400 K and Block B at 300 K both have mass 1 kg and specific heat 400 J/kg·K. What is the change in entropy of the universe?

An ideal gas undergoes an adiabatic process from state (P₁, V₁, T₁) to (P₂, V₂, T₂) with γ = 1.4. If volume increases by 50%, the temperature ratio T₂/T₁ is approximately:

A refrigerator operates with a COP (Coefficient of Performance) of 4 between temperatures 250 K and 350 K. What is the theoretical maximum COP possible?