The First Law of Thermodynamics, represented by the mathematical equation $Q = \Delta U + W$, is essentially a localized restatement of the universal principle of:

A Carnot engine operating between temperatures T1 (hot) and T2 (cold) has a maximum efficiency of:

The efficiency of a Carnot engine working between temperatures T1 (hot) and T2 (cold) is given by:

A theoretical ideal gas undergoes a reversible thermodynamic cycle 20. During the adiabatic expansion phase, the total heat exchange ($Q$) with the surroundings is strictly:

A theoretical ideal gas undergoes a reversible thermodynamic cycle 18. During the adiabatic expansion phase, the total heat exchange ($Q$) with the surroundings is strictly:

A theoretical ideal gas undergoes a reversible thermodynamic cycle 17. During the adiabatic expansion phase, the total heat exchange ($Q$) with the surroundings is strictly:

A theoretical ideal gas undergoes a reversible thermodynamic cycle 16. During the adiabatic expansion phase, the total heat exchange ($Q$) with the surroundings is strictly: