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
The correct answers 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