Question

BHP of an engine indicates

• A. Power in cylinder
• B. Power on fly wheel
• C. Fric honal power
• D. Power at RTO pully

Hint:

- Power developed in the cylinder = Indicated Horsepower (IHP).
- Power available at the crankshaft/flywheel = Brake Horsepower (BHP).
- BHP is always less than IHP due to friction losses (FHP).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Engine power is expressed in horsepower (HP) and classified into several terms based on where and how it is measured.
Key Formula or Approach:
The relationship between the different horsepower terms in an internal combustion engine is:
\[ \text{Brake Horsepower (BHP)} = \text{Indicated Horsepower (IHP)} - \text{Friction Horsepower (FHP)} \]

Step 2: Detailed Explanation:
Let us define these horsepower terms:
- Indicated Horsepower (IHP): The theoretical power developed inside the engine cylinder by the expansion of combustion gases. It does not account for mechanical losses.
- Friction Horsepower (FHP): The power lost due to friction between moving engine parts (such as pistons, bearings, and gears).
- Brake Horsepower (BHP): The actual, useful power available at the engine crankshaft or flywheel.
It is measured using a dynamometer or brake applied to the engine's output shaft or flywheel, which is why it is called brake horsepower.
Therefore, BHP represents the net power output available on the flywheel after mechanical losses have been deducted.

Step 3: Final Answer:
BHP of an engine indicates the useful power available on the flywheel.