Question

Given below are two statements:
Statement I: The function of governor is to regulate mean speed of engine when there are variations in load
Statement II: A governor is said to be hunting if the speed of engine remains constant at the mean speed
In light of the above statements, choose the most appropriate answer from the options given below

• A. Both Statement I and Statement II are correct
• B. Both Statement I and Statement II are incorrect
• C. Statement I is correct but Statement II is incorrect
• D. Statement I is incorrect but Statement II is correct

Hint:

To distinguish between the key engine components:
- Governor \(\rightarrow\) Regulates speed over long periods due to load variations.
- Flywheel \(\rightarrow\) Regulates speed within a single cycle due to torque fluctuations.
- Hunting \(\rightarrow\) Constant oscillation of speed caused by an over-sensitive governor.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Governors are mechanical control devices used in engines to regulate the mean speed of the engine when the external load varies.
They achieve this by adjusting the fuel or working fluid supply in response to speed changes.

Step 2: Detailed Explanation:
Let us evaluate both statements:
- Statement I: "The function of a governor is to regulate the mean speed of the engine when there are variations in load."
This is correct.
When the load on an engine increases, the engine slows down. The governor detects this speed drop and automatically increases the fuel supply to bring the engine back to its target mean speed.
Conversely, if the load decreases, the engine speeds up, and the governor reduces the fuel supply.
(Note: Do not confuse this with a flywheel, which minimizes speed fluctuations within a single operating cycle due to torque variations, rather than load variations).
- Statement II: "A governor is said to be hunting if the speed of the engine remains constant at the mean speed."
This is incorrect.
Hunting is an undesirable operational problem that occurs when a governor is over-sensitive.
When a small change in speed occurs, an over-sensitive governor makes an excessively large adjustment to the fuel supply.
This causes the engine speed to overshoot the mean speed in the opposite direction.
The governor then over-corrects again, causing the engine speed to continuously fluctuate (oscillate) above and below the desired mean speed.
Therefore, hunting refers to speed instability, not constant speed.
Thus, Statement I is correct, but Statement II is incorrect.

Step 3: Final Answer:
The correct option is (C).