Question

The brake output per unit of piston displacement is defined as brake power.

(a) True

(b) False

I have been asked this question in semester exam.

My enquiry is from Engine Power in chapter Measurements and Testing/Performance Parameters and Characteristics of IC Engine

Answer 1

The correct answer is:

(b) False

Explanation:

The statement is incorrect. The brake output per unit of piston displacement is not defined as brake power. Brake power (BP) refers to the actual mechanical power output of the engine at the crankshaft, measured after losses due to friction in the engine components (like bearings and the crankshaft itself). 

What you are referring to is specific brake power (SBP), which is the brake power per unit of engine displacement or per unit of engine mass. Brake power is not directly defined by piston displacement.