Question

Which of the following processes is reversible?

• A. Transfer of heat by radiation
• B. Electrical heating of a nichrome wire
• C. Transfer of heat by conduction
• D. Isothermal compression

Answer 1

The Correct Option is D

The question asks us to identify which of the given processes is reversible. To understand this, we must first define what makes a process reversible in thermodynamics.

Concept of Reversible Processes

A reversible process is an ideal process that, once it has taken place, can be reversed without leaving any net change in the system and surroundings. Reversible processes are quasi-static, where the system is in equilibrium with its surroundings at all steps. However, in reality, perfectly reversible processes are theoretical concepts as all natural processes involve some degree of irreversibility.

Analysis of Options

1. Transfer of heat by radiation: Heat transfer by radiation involves the emission and absorption of energy and is generally irreversible because energy disperses into the surroundings in a non-equilibrium manner.
2. Electrical heating of a nichrome wire: This involves converting electrical energy into thermal energy, causing an increase in entropy (unusable energy), making it irreversible.
3. Transfer of heat by conduction: Heat conduction occurs due to temperature gradients, and once heat has moved from a higher to a lower temperature region, the process is not easily reversible without external work, making it irreversible.
4. Isothermal compression: An isothermal process occurs at a constant temperature. If a system undergoes slow compression or expansion such that the process is quasistatic and the system remains in thermal equilibrium with a heat reservoir, it can theoretically be reversed with no net change in the universe, making it reversible.

Conclusion

Based on the analysis, the correct answer to the given question is:

Isothermal compression

This process can theoretically be performed in a reversible manner, whereas the other options inherently involve irreversible processes due to entropy increase or dissipation of energy.