Question

An engine's ability to perform work:

a. is always equal to the energy of its fuel
b. is always less than the energy of its fuel
c. is always greater than the energy of its fuel

Answer 1

An engine's ability to perform work is always less than the energy of its fuel. (b)

(That's a transformation from chemical energy to mechanical energy. Some energy is always lost as heat during a transformation. Nothing is ever 100% efficient.)