Ten questions. The result tells you which lessons you may skip.
An engine takes \(1000\,\text{J}\) from its source and gives \(700\,\text{J}\) to its sink in each cycle. Its efficiency is
Over one complete cycle of a heat engine, the change in the internal energy of its working substance is
A machine that takes heat from the sea and turns all of it into work, cycle after cycle, would break
Which of these is irreversible?
A Carnot engine works between \(227\,°\text{C}\) and \(27\,°\text{C}\). Its efficiency is
An inventor claims an engine working between \(600\,\text{K}\) and \(300\,\text{K}\) with an efficiency of \(55\,\%\). The claim is
A Carnot refrigerator keeps its inside at \(260\,\text{K}\) in a kitchen at \(312\,\text{K}\). Its coefficient of performance is
One kilogram of ice melts at \(273\,\text{K}\), with \(L_f = 3.34 \times 10^5\,\text{J/kg}\). Its entropy increases by about
In a reversible adiabatic expansion of an ideal gas, the entropy of the gas
On a T-S diagram, the area under a reversible path equals