Correct option is C
The
mechanical efficiency of an engine is defined as the ratio of brake power (BP) to indicated power (IP). It measures the effectiveness with which the indicated power, generated inside the engine cylinder, is converted into useful brake power at the engine crankshaft.
ηmechanical = Brake Power (BP)/Indicated Power (IP)×100
Brake Power (BP): The actual power available at the crankshaft after losses due to friction.
Indicated Power (IP): The power developed inside the cylinder without accounting for frictional losses.
Information Booster:
· Mechanical efficiency is always less than 100% due to friction losses.
· Frictional power = Indicated Power – Brake Power.
· Increasing lubrication and minimizing mechanical losses improves mechanical efficiency.
