Test: Governors - 1 - Mechanical Engineering MCQ

• Equilibrium Speed: The equilibrium speed of a governor is the speed at which the balls settle when the system is in balance.


• Constant for all Radii: When the equilibrium speed remains constant for all radii of rotation of the balls, it means that the governor is able to maintain a stable speed regardless of the position of the balls.


• Isochronous Governor: A governor that maintains a constant speed regardless of the load variations is known as an isochronous governor.


• Significance: An isochronous governor is considered ideal for applications where a constant speed is required, such as in engines or generators.


• Stability: The stability of the governor is crucial to ensure that it can effectively regulate the speed of the system without fluctuations.

Therefore, in this scenario, if the equilibrium speed is constant for all radii of rotation of balls, the governor is said to be isochronous, meaning it can maintain a constant speed regardless of the external conditions.

• Centrifugal Force: This force is the outward force experienced by objects moving in a circular path. In the case of a governor, the balls move outward due to centrifugal force.



• Inertia Force: This force is related to the resistance of an object to changes in its motion. In the case of the governor, the balls have inertia that opposes their outward movement.



• Effort: Effort is the force applied to overcome a resistance. In the governor, the effort is applied to control the movement of the balls.



• Controlling Force: This force is the force that resists the outward movement of the balls in the governor. It is responsible for maintaining the desired speed or position of the governor.

Wilson-Harnell governor (also known as radial spring controller) uses two parallel springs alongwith an auxiliary spring.

• Governor Function: The governor is a device used in engines to regulate the speed of the engine by controlling the flow of fuel or working fluid based on the speed of the engine.


• Effort of Governor: The effort of the governor refers to the force exerted by the governor on the sleeve to control the speed of the engine.


• Role of Sleeve: The sleeve in the governor mechanism moves up and down based on the speed of the engine. The force exerted by the governor on the sleeve determines the position of the sleeve and hence regulates the flow of fuel or working fluid.


• Importance of Effort: The correct amount of effort exerted by the governor is crucial for maintaining the desired speed of the engine and preventing over-speeding or under-speeding.


• Correct Answer: In this question, the correct answer is sleeve as the effort of the governor is exerted on the sleeve to control the engine speed.

 pendulum type of governor cannot possibly be isochronous because it is impossible to have two positions of the balls at the same speed.

The governor controls the supply of working fluid to the engine in accordance with varying load conditions, and keeps the mean speed within certain limits.

• Watt governor: A Watt governor is a type of centrifugal governor that uses rotating balls to control the speed of an engine or machine.


• Speed range: The speed range of a Watt governor refers to the range of speeds at which it can effectively control the speed of the engine or machine.


• Options: The given options for the speed range of a Watt governor are:




• A: 20 to 50 rpm


• B: 60 to 80 rpm


• C: 80 to 120 rpm


• D: 120 to 200 rpm




• Correct Answer: The correct answer is B: 60 to 80 rpm as this is the speed range within which a Watt governor is typically designed to operate effectively.