Engineering Questions with Answers - Multiple Choice Questions

# Machine Dynamics MCQ – Belt Transmission Dynamometer-Froude or Throneycraft Transmission Dynamometer

1 - Question

Which of the following is a function of a belt transmission dynamometer?
a) Measure the difference in tension of the belts
b) Measuring speed of an engine
c) Measuring power of an engine
d) Measuring friction

Explanation: The tangential force on the pulley which is driven is equal to the difference between the tensions in the tight and slack sides of the belt. A belt dynamometer is inserted to measure directly the difference between the tensions of the belt.

2 - Question

Belt transmission dynamometer is an absorption dynamometer.
a) True
b) False

Explanation: Belt transmission dynamometer uses the energy from the engine to do useful work, unlike absorption dynamometer where this energy gets converted into heat. Hence it is a transmission dynamometer.

3 - Question

Which of the following dynamometers work in a similar way to belt transmission dynamometer?
a) Epicyclic train dynamometer
b) Rope brake dynamometer
c) Prony brake dynamometer
d) Froude or Throneycroft Transmission Dynamometer Dynamometer

Explanation: Rope brake and Prony brake dynamometers are absorption dynamometers hence they function differently. Froude or Throneycroft Transmission Dynamometer Dynamometer is another name for belt transmission dynamometer.

4 - Question

Brake power of an engine is independent of the following quantity _______
a) Difference in band torques
b) Diameter of puller
c) Speed of engine
d) Friction

Explanation: Braking power of the engine is given by the equation:
B.P = (T1-T2)πDN/60
hence it is independent of friction.

5 - Question

For a belt transmission dynamometer, if the diameter of pully is doubled and speed of rotation is halved, then the new braking power will be ________
a) Halved
b) Doubled
d) Remain same

Explanation: Braking power of the engine is given by the equation
B.P = (T1-T2)πDN/60
if Diameter is doubled and speed is halved it will have no effect in the existing brake power.

6 - Question

Calculate brake power from the following data:
T1 = 1500N
T2 = 800N
Diameter of pulley = 30cm
Speed of engine shaft = 600rpm
a) 6.5 kW
b) 13 kW
c) 3.2 kW
d) 7 kW

Explanation: B.P = (T1-T2)πDN/60
T1 = 1500N
T2 = 800N
D = 0.3 m
N = 600 rpm
therefore BP = 6.5 kW.

7 - Question

To prevent the rotation caused by frame, which of the following quantity is added?
a) Weight at a distance
b) Weight at the centre
c) Ball bearings
d) Welded joints

Explanation: The frame causes a rotation in an anticlockwise direction, to prevent this rotation a weight is added at a certain distance from the shaft.

8 - Question

Brake power of an engine is directly proportional to the speed of engine.
a) True
b) False