Engineering Questions with Answers - Multiple Choice Questions

# Machine Dynamics MCQ – Brakes and Dynamometers

1 - Question

The brakes commonly used in railway trains is
a) shoe brake
b) band brake
c) band and block brake
d) internal expanding brake

View Answer

Answer: a
Explanation: A single block or shoe brake consists of a block or shoe which is pressed against the rim of a revolving brake wheel drum. The block is made of a softer material than the rim of the wheel. This type of a brake is commonly used on railway trains and tram cars.

2 - Question

The brake commonly used in motor cars is
a) shoe brake
b) band brake
c) band and block brake
d) internal expanding brake

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Answer: d
Explanation: The internal expanding type of brake is commonly used in motor cars and light trucks.

3 - Question

When brakes are applied to all the four wheels of a moving car, the distance travelled by the car before it is brought to rest, will be
a) maximum
b) minimum
c) equal
d) none of the mentioned

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Answer: b
Explanation: When the brakes are applied to all the four wheels, the braking distance (i.e. the distance in which the vehicle is brought to rest after applying the brakes) will be the least. It is due to this reason that the brakes are applied to all the four wheels.

4 - Question

Which of the following is an absorption type dynamometer ?
a) prony brake dynamometer
b) epicyclic-train dynamometer
c) torsion dynamometer
d) none of the mentioned

View Answer

Answer: a
Explanation: Absorption type dynamometers are
1. Prony brake dynamometer,
2. Rope brake dynamometer.

5 - Question

The transmission type of dynamometer is a
a) prony brake dynamometer
b) epicyclic-train dynamometer
c) torsion dynamometer
d) none of the mentioned

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Answer: c
Explanation: Transmission type dynamometers are
1. Epicyclic-train dynamometer,
2. Belt transmission dynamometer,
3. Torsion dynamometer.

6 - Question

The material used for the brake lining should have
a) It should have low wear rate.
b) It should have high heat resistance.
c) It should have high heat dissipation capacity.
d) All of the mentioned

View Answer

Answer: d
Explanation: The material used for the brake lining should have the following characteristics:
1. It should have high coefficient of friction with minimum fading.
2. It should have low wear rate.
3. It should have high heat resistance.
4. It should have high heat dissipation capacity.
5. It should have adequate mechanical strength.
6. It should not be affected by moisture and oil.

7 - Question

The capacity of a brake depends upon
a) The unit pressure between the braking surfaces,
b) The coefficient of friction between the braking surfaces,
c) The peripheral velocity of the brake drum
d) All of the mentioned

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Answer: d
Explanation: The capacity of a brake depends upon the following factors :
1. The unit pressure between the braking surfaces,
2. The coefficient of friction between the braking surfaces,
3. The peripheral velocity of the brake drum,
4. The projected area of the friction surfaces, and
5. The ability of the brake to dissipate heat equivalent to the energy being absorbed.

8 - Question

For high speed engines, the cam follower should move with
a) uniform velocity
b) simple harmonic motion
c) uniform acceleration and retardation
d) cyclodial motion

View Answer

Answer: d
Explanation: For high speed engines, the cam follower should move with cyclodial motion. For S.H.M. cam, the acceleration of the follower at the ends of the stroke and aimed stroke respectively, is
maximum and zero.