Question

The frictional power (F.P) is given by ____________

(a) F.P. = B.P.-I.P.

(b) F.P. = I.P.-B.P.

(c) F.P. = B.P./I.P.

(d) F.P. = I.P./B.P.

The question was posed to me during an interview for a job.

This interesting question is from Engine Power in portion Measurements and Testing/Performance Parameters and Characteristics of IC Engine

Answer 1

The correct answer is:

(b) F.P. = I.P. - B.P.

Explanation:

Frictional Power (F.P.) is the power lost due to friction in the engine components. It is calculated by subtracting the brake power (B.P.) from the indicated power (I.P.). 

- Indicated Power (I.P.) is the total power generated by the combustion process in the engine.

- Brake Power (B.P.) is the usable power available at the engine's crankshaft, after losses due to friction.

  

So, the difference between the two gives the frictional power that is consumed by engine friction and other internal resistances.