Please answer ASAP!! How do we define energy efficiency?

А.) the ratio of the actual output energy to the input energy

B.) the ratio of power gain to power loss

C.) the product of input power and output power

D.) the sum of potential and kinetic energy

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

Adouble-strand no. 60 roller chain is used to transmit power between a 13-tooth driving sprocket rotating at 300 rev/min and a 52-tooth driven sprocket. a) what is the allowable horsepower of this drive? b) estimate the center-to-center distance if the chain length is 82 pitches. c) estimate the torque and bending force on the driving shaft by the chain if the actual horsepower transmitted is 30 percent less than the corrected (allowable) power.

Determine whether or not it is possible to compress air adiabatically from k to 140 kpa and 400 k. what is the entropy change during this process?