Question 131Motor Plants - QMED

The correct answer is B) brake horsepower. Brake horsepower (BHP) is the most important factor in engine performance as it represents the actual power output at the end of the crankshaft available for doing work. BHP accounts for all the power losses due to friction, pumping, and other mechanical inefficiencies within the engine, making it the most accurate measure of the engine's useful power output. The other options are incorrect because: A) Indicated horsepower (IHP) represents the power generated by the engine's cylinders before accounting for power losses. C) Net horsepower (NHP) is the power delivered to the propeller, which is lower than BHP due to transmission losses. D) Friction horsepower (FHP) represents the power lost due to internal engine friction, which is not the actual power output available for doing work.