Question

Which one of the following options is correct for \[ q = -ve, \, w = +ve \{ (where \(q\) and \(w\) are heat and work respectively)} \]

• A. Isothermal irreversible expansion of an ideal gas with constant external pressure.
• B. Isothermal irreversible compression of an ideal gas with constant external pressure.
• C. Isothermal reversible expansion of an ideal gas against constant external pressure.
• D. Irreversible expansion of an ideal gas into vacuum.

Hint:

For an irreversible process, when heat is lost (\(q = -ve\)) and work is done by the surroundings on the system (\(w = +ve\)), the process is usually a compression.

Answer 1

The Correct Option is B

When \(q = -ve\) and \(w = +ve\), it implies that the process is an irreversible compression, meaning that the gas is compressed and work is done by the surroundings on the gas. The heat flow is negative (\(q = -ve\)), which indicates that the gas is losing heat during the compression process. Therefore, this situation is described by an isothermal irreversible compression of an ideal gas at constant external pressure.