1. What are the lower and upper limits on:
(a) the efficiency of an engine,
(b) the coefficient of performance for a refrigerator?
2. Consider one mole of an ideal gas with v degrees of freedom per molecule and temperature T. In terms of v and T, what would be the slope of the curve on a T-S plot for
(a) isochoric heat addition,
(b) isobaric heat addition,
(c) isothermal heat addition?
(d) Do these have curvature and, if so, are they concave upwards or downwards?