Engineering Questions with Answers - Multiple Choice Questions

Machine Dynamics MCQ– Hartung Governor

1 - Question

If the controlling force line for a spring controlled governor when produced intersects the Y-axis at the origin, then the governor is said to be
a) stable
b) unstable
c) isochronous
d) none of the mentioned

View Answer

Answer: c
Explanation: If the controlling force line for a spring controlled governor when produced intersects the Y-axis at the origin, then the governor is said to be isochronous.
A spring controlled governor is said to be stable if the controlling force line when produced intersects the Y-axis below the origin.
If the controlling force line for a spring controlled governor when produced intersects the Y-axis at the origin, then the governor is said to be unstable.

2 - Question

If the controlling force line for a spring controlled governor when produced intersects the Y-axis at the origin, then the governor is said to be unstable.
a) True
b) False

View Answer

Answer: a
Explanation: A spring controlled governor is said to be stable if the controlling force line when produced intersects the Y-axis below the origin.
If the controlling force line for a spring controlled governor when produced intersects the Y-axis at the origin, then the governor is said to be unstable.

3 - Question

The relation between the controlling force (Fc) and radius of rotation (r) for a stable spring controlled governor is
a) Fc = ar + b
b) Fc = ar – b
c) Fc = ar
d) Fc = a/r + b

View Answer

Answer: b
Explanation: The relation between the controlling force (FC) and the radius of rotation (r) for the stability of spring controlled governors is given by the following equation
FC = a.r – b

4 - Question

A spring controlled governor is said to be unstable, if the relation between the controlling force (Fc) and radius of rotation(r) is Fc = ar
a) True
b) False

View Answer

Answer: b
Explanation: A governor is said to be unstable and the relation between the controlling force and the radius of
rotation is, therefore
FC = a.r + b

5 - Question

When the relation between the controlling force (Fc) and radius of rotation (r) for a spring controlled governor is Fc = ar + b, then the governor will be
a) stable
b) unstable
c) isochronous
d) none of the mentioned

View Answer

Answer: b
Explanation: A governor is said to be unstable and the relation between the controlling force and the radius of
rotation is, therefore
FC = a.r + b

6 - Question

A Hartnell governor has its controlling force (Fc) given by Fc = ar + b, where r is the radius of rotation and a and b are constants. The governor becomes isochronous when
a) a is + ve and b = 0
b) a = 0 and b is +ve
c) a is +ve and b is -ve
d) a is +ve and b is also +ve

View Answer

Answer: a
Explanation: None

7 - Question

Calculate the vertical height of a Watt governor when it rotates at 60 r.p.m.
a) 0.248 m
b) 0.248 m
c) 0.448 m
d) 0.548 m

View Answer

Answer: a
Explanation: Given : N1 = 60 r.p.m. ; N2 = 61 r.p.m.
Initial height
We know that initial height,
h1 = 895/(N1)2
= 895/602 = 0.248 m

8 - Question

The power of a governor is the work done at
a) the governor balls for change of speed
b) the sleeve for zero change of speed
c) the sleeve for a given rate of change of change
d) each governor ball for given percentage change of speed

View Answer

Answer: c
Explanation: Power of Governor: The work done by the governor on the sleeve to its equilibrium position for the fractional change in speed of governor is known as power of governor.
It is actually a work done. Power = Main force × Sleeve movement.

9 - Question

In a governor, if the equilibrium speed is constant for all radii of rotation of balls, the governor is said to be
a) Stable
b) unstable
c) inertial
d) isochronous

View Answer

Answer: d
Explanation: The governor is said to be Isochronous if the equilibrium speed is constant for all radii of rotation of balls.

10 - Question

A governor is said to be isochronous when the equilibrium speed is
a) variable for different radii of rotation of governor balls
b) constant for all radii of rotation of the balls within the working range
c) constant for particular radii of rotation of governor balls
d) constant for only one radius of rotation of governor balls

View Answer

Answer: b
Explanation: Isochronism in governor means constant equilibrium speed for all the radii of rotation.