Engineering Questions with Answers - Multiple Choice Questions

# Machine Dynamics MCQ – Effort and Power of a Governor

1 - Question

The effort of a governor is the _________ force exerted at the sleeve for a given percentage change of speed.
a) Maximum
b) Minimum
c) Mean
d) Reciprocal of

View Answer

Answer: c
Explanation: The effort of a governor is the mean force exerted at the sleeve for a given percentage change of speed or lift of the sleeve.

2 - Question

When there is no force on the sleeve, then the governor must be running steadily.
a) True
b) False

View Answer

Answer: a
Explanation: When a governor is running steadily then it is under the condition that it experiences no force on its sleeve. Forces acting on the sleeve results in change of speed of the governor.

3 - Question

Resistance in a sleeve which results in opposing the motion is caused by _______
a) Change of speed
b) Change of weight
c) Isochronism
d) Change in type of governor

View Answer

Answer: a
Explanation: When the speed at which the governor is undergoing motion changes, there is a resistance at the sleeve which opposes its motion.

4 - Question

Power of a governor depends on which of the following factor?
a) Mean effort
b) Maximum effort
c) Minimum effort
d) Weight of the engine

View Answer

Answer: a
Explanation: The power of a governor is the work done at the sleeve for a given percentage change of speed. It is the product of the mean value of the effort and the distance through which the sleeve moves.

5 - Question

Find the power of the governor if the Mean effort is 50 N and sleeve lift is 100 mm.
a) 5N-m
b) 25N-m
c) 250N-mm
d) 50N-mm

View Answer

Answer: a
Explanation: Power is given by
(mean effort) x (sleeve lift)
= 50×0.1 N-m
= 5N-m.

6 - Question

If the sleeve lift is 80 mm and Power generated by the governor is 6 N-m, then find the mean effort.
a) 7.5 N
b) 15 N
c) 20 N
d) 30 N

View Answer

Answer: a
Explanation: Power is given by
mean effort x sleeve lift
6 = 0.8xmean effort
6/0.8 = 7.5 N.

7 - Question

If the mean effort is doubled and the sleeve lift is halved, If P was the original power then what will be the power post the changes?
a) 2P
b) P
c) 4P
d) P/2

View Answer

Answer: b
Explanation: Power is given by:
mean effort x sleeve lift
since power is directly proportional to the sleeve lift and mean effort, hence doubling one factor and reducing the other to half has no effect on the power.

8 - Question

Power of a governor is the work done by the sleeve for a given percentage change in speed.
a) True
b) False

View Answer

Answer: b
Explanation: Power of the governor is the work done at the sleeve for a given percentage change of speed. It is important to note that the work should be done at the sleeve and not at any other part of the governor.