Correct Answer - Option 3 : PLAN/2
Concept:
Indicated Power for four-stroke engine is given by,
\(I.P.~=~\frac{PLAN}{ 2}\)
where P = mean effective pressure in N/m2, L = stroke length in m, A = Area of cross-section of the cylinder in m2, N = rpm of the engine crankshaft
\(η_m~=~\frac{B.P.}{I.P.}\)
where ηm = mechanical efficiency, B.P. = brake power, I.P. = Indicated power