Author Question: What makes refrigerators and air conditioners possible, in view of the second law of thermodynamics? ... (Read 27 times)

SO00 · **on:** Jul 28, 2018

What makes refrigerators and air conditioners possible, in view of the second law of thermodynamics?
a. The fact that heat naturally moves from cooler regions to hotter ones.
b. The addition of mechanical work to the system.
c. The chance occurrences of heat flow from cooler to hotter systems.
d. The use of electricity, not heat.
e. The fact that no energy is wasted as heat in this kind of system.

Question 2

What is the approximate efficiency of a contemporary steam engine (such as one that drives an electric generator in a power plant)?
a. About 10.
b. About 35.
c. Zero.
d. About 50.
e. About 61.