DC -- 15.5

Heat pumps, air conditioners, and refrigerators utilize heat transfer from cold to hot. They require ---

• An increase in temperature

• An increase in pressure

• An input of Work

• An increase in volume

Air conditioners and refrigerators involve heat transfer Q_c from a ---

• Hot environment

• Humid environment

• Vacuum environment

• Cool environment

A heat pump transfers heat Q_h transfer to occur ---

• Into a warm environment

• Into a vacuum

• Into a humid environment

• Into a cooler environment

Heat pumps, air conditioners, and refrigerators are heat engines operated ----

• Backward

• Upward

• Sideways

• Outward

This is a diagram of ---

• a generator

• a Carnot engine

• a condenser

• a heat pump

What does COP_hp represent?

• the mechanical energy constant of the universe

• heat pump's coefficient of performance

• the efficiency of a heat pump

• the temperature constant of a heat pump