Ahand crank generator produces electricity when the handle is turned. the generator is hooked up to a light bulb. when the handle is turned, the light bulb lights up. which of these is the best explanation of what is occurring here? a) the work done on the handle is converted into electricity and used to light the bulb. b) turning the handle pushes electrons in a wire through the light bulb. c) the generator excites atoms which makes the atoms glow. d) kinetic energy is lost and heat is generated.

4r-134a enters the condenser of a residential heat pump at 800 kpa and 50°c at a rate of 0.022 kg/s and leaves at 750 kpa subcooled by 3°c. the refrigerant enters the compressor at 200 kpa superheated by 4°c determine (a) the isentropic efficiency of the compressor, (b) the rate of heat supplied to the heated room, and (c) the cop of the heat pump. also, determine (d) the cop and rate of heat supplied to the heated room if this heat pump operated on the ideal vapor-compression cycle between the pressure limits of 200 and 800 kpa. (0.757, 4.37 kw, 5.12, 6.18, 3.91 kw)