Which of the following proposed heat engines violate the second law of thermodynamics? Select all that apply.?
a) A heat engine with no heat rejection step.
b) A heat engine with an efficiency greater than the efficiency of a Carnot heat engine operating between the same two temperatures.
c) A heat engine with a thermal efficiency of 100 percent.
d) A heat engine with an efficiency greater than the efficiency of a totally reversible heat engine operating between the same two temperatures.