Test: Flywheel & Governor - 2 - Mechanical Engineering MCQ

A spring controlled governor is found unstable. It can be made stable by

Consider the following parameters:

1. Limit of peripheral speed
2. Limit of centrifugal stress
3. Coefficient of fluctuation of speed
4. Weight of the rim

Which of these parameters are used in the calculation of the diameter of fly wheel rim?

Which one .of the following statement is correct?

A governor will be stable if the radius of rotation of the balls

What is the value of the radius of gyration of disc type flywheel as compared to rim type flywheel for the same diameter?

The sensitivity of an isochronous governor is

For minimizing speed fluctuations of an engine as a prime mover, it must have

The nature of the governors is shown by the graph between radius (r) of rotation and controlling force (F). Which of the following is an isochronous governor?

Match List-I with List-II and select the correct answer using the codes given below the Lists:

A Hartnell governor has its controlling force F given by

F = p + qr
Where, is the radius of the balls and p and q are constants.
The governor becomes isochronous when

A flywheel is fitted to the crankshaft of an engine having 'E' amount of indicated work per revolution and permissible limits of co-efficient of fluctuation of energy and speed as K_e and K_s respectively.

The kinetic energy of the flywheel is then given by

Assertion (A): The degree of hunting with an unstable governor will be less than with an isochronous governor.

Reason (R): With an unstable governor, once the sleeve has moved from one extreme position to the other, a finite change of speed is required to cause it to move back again.

If the rotating mass of a rim type fly wheel is distributed on another rim type flywheel whose mean radius is half mean radius of the former, then energy stored in the latter at the same speed will be  

Consider the following statements:

1. The condition of stability of a governor requires that the slope of the controlling force curve should be less than that of the line representing the centripetal force at the equilibrium speed under consideration.
2. For a centrifugal governor when the load on the prime mover drops suddenly, the sleeve should at once reach the lower-most position.

Which of the statements given above is/are correct?

For the same indicated work per cycle, mean speed and permissible fluctuation of speed, what is the size of flywheel required for a multi-cylinder engine in comparison to a single cylinder engine?

The controlling force curves for a spring-controlled governor are shown in the above figure. Which curve represents a stable governor?

The turning moment diagram for a single cylinder double acting steam engine consists of +ve and –ve loops above and bellow the average torque line. For the +ve loop, the ratio of the speeds of the flywheel at the beginning and the end is which one of the following?

Consider the following statements concerning centrifugal governors:

1. The slope of the controlling force curve should be less than that of the straight line representing the centripetal force at the speed considered for the stability of a centrifugal governor.
2. Isochronism for a centrifugal governor can be achieved only at the expense of stability.
3. When sleeve of a centrifugal governor reaches its topmost position, the engine should develop maximum power.

Which of the statements given above is/are correct?

A certain machine requires a torque of (500 + 50Sinθ) KNm to derive it, θ where is the angle of rotation of shaft measured from certain datum. The machine is directly coupled to an engine which produces a toques (500 +50sin θ) KNm in a cycle how many times the value of torque of machine and engine will be identical

The height of a simple Watt governor running at a speed ‘N’ is proportional to

In which of the following case, the turning moment diagram will have least variations:

The height of Watt's governor is

The given figure shows the output torque plotted against crank positions for a single cylinder fourstroke-cycle engine. The areas lying above the zero-torque line represent positive work and the areas below represent negative work. The engine drives a machine which offers a resisting torque equal to the average torque. The relative magnitudes of the hatched areas are given by the numbers (in the areas) as shown:

During the cycle, the minimum speed occurs in the engine at

The plots of controlling force versus radii of rotation of the balls of spring controlled governors are shown in the given diagram. A stable governor is characterised by the curve labelled

In a four stroke I.C. engine, the turning moment during the compression stroke is

For a spring controlled governor to be stable, the controlling force (F) is related to the radius (r) by the equation

The amount of energy absorbed by a flywheel is determined from the

The sensitivity dh/dN of a given Porter Governor. Where 'h' is the height of the pin point A from the sleeve and N is the ripe. m., is proportional to