Heat and Thermodynamics — Prelims Questions

Consider the following statements regarding heat transfer mechanisms: 1. Conduction is the primary mode of heat transfer in metals. 2. Convection requires a fluid medium and involves the bulk movement of particles. 3. Radiation can transfer heat through a vacuum and is the fastest mode of heat transfer. Which of the statements given above are correct?

Which of the following statements best describes the Second Law of Thermodynamics? (A) Energy can neither be created nor destroyed. (B) If two systems are in thermal equilibrium with a third system, they are in thermal equilibrium with each other. (C) The total entropy of an isolated system can only increase over time. (D) Absolute zero temperature is theoretically unattainable.

Which of the following real-world phenomena is an application of the latent heat of vaporization? (A) The cooling effect felt after sweating. (B) The expansion of railway tracks in summer. (C) The working of a solar water heater. (D) The high specific heat capacity of water moderating coastal climates.

Consider a refrigerator operating in a kitchen. Which of the following statements is thermodynamically correct? (A) It transfers heat from a hot reservoir to a cold reservoir without external work. (B) Its Coefficient of Performance (COP) can be greater than 1. (C) It violates the First Law of Thermodynamics by creating coldness. (D) It is a type of heat engine operating in reverse, with 100% efficiency.

The Joule-Thomson effect is primarily utilized in which of the following applications? (A) Power generation in thermal power plants. (B) Liquefaction of gases and refrigeration. (C) Measuring high temperatures in furnaces. (D) Designing efficient solar panels.