Which of the process described below are irreversible?
Which of the process described below are irreversible?

a) the increase in temperature of an iron rod by hammering it

b) a gas in a small container at a temperature T1 is brought in contact with a big reservoir at a higher temperature T2 which increases the temperature of the gas

c) a quasi-static isothermal expansion of an ideal gas in a cylinder fitted with a frictionless piston

d) an ideal gas is enclosed in a piston-cylinder arrangement with adiabatic walls. A weight W is added to the piston resulting in compression of gas

Answer:

The correct options are

a) the increase in temperature of an iron rod by hammering it

b) a gas in a small container at a temperature T1 is brought in contact with a big reservoir at a higher temperature T2 which increases the temperature of the gas

d) an ideal gas is enclosed in a piston-cylinder arrangement with adiabatic walls. A weight W is added to the piston resulting in compression of gas

Explanation: In all of the examples above, the system’s initial state cannot be restored. Any process that isn’t completely reversible is irreversible. Conduction, radiation, radioactive decay, and other natural processes are all irreversible. All practical processes are irreversible, including free expansion, Joule-Thomson expansion, and electrical heating of a wire.