Question

The ratio of the work obtained at the crankshaft in a given time to the energy supplied during the same time is called ______________

(a) mechanical efficiency

(b) overall efficiency

(c) indicated thermal efficiency

(d) volumetric efficiency

The question was asked in an online interview.

My question is taken from Engine Efficiencies in chapter Measurements and Testing/Performance Parameters and Characteristics of IC Engine

Answer 1

The correct answer is:

(a) mechanical efficiency

Mechanical efficiency is the ratio of the work obtained at the crankshaft (brake power) to the energy supplied (indicated power) during the same period. It indicates how effectively an engine converts the energy generated by combustion into useful work, accounting for mechanical losses in components such as the crankshaft, pistons, and bearings.