# MCQs on Brakes

1 - Question

The energy absorb by brake is always kinetic.

a) No, potential
b) Kinetic or potential
c) Potential
d) Strain Energy

Explanation: It can be either kinetic or potential.

2 - Question

Pneumatic brakes are same as electrical brakes.

a) Yes both are concerned with electricity
b) No, one deals with pressure and other with electricity
c) Yes both deals with pressure
d) None of the listed

Explanation: Pneumatic brakes are operated by fluid pressure.

3 - Question

a) True
b) False

Explanation: Disc brakes are axial brakes.

4 - Question

Internal shoe brakes are radial while external shoe brakes are axial brakes.

a) True
b) False

Explanation: Both internal and external shoe brakes are radial brakes.

5 - Question

A solid cast iron disk of mass 1000kg is rotating at 350rpm. Diameter of the disk is 1m and time taken to come to stop the disk by brake is 1.6sec.Calculate energy absorbed by the brake if square of radius of gyration is 0.2.

a) None of the mentioned
b) 134.3kJ
c) 165.3kJ
d) 134.2kJ

Explanation: E=mk²ω²/2.

6 - Question

A solid cast iron disk of mass 1000kg is rotating at 350rpm. Diameter of the disk is 1m and time taken to come to stop the disk by brake is 1.6sec.Square of radius of gyration is 0.2. Calculate the average angular velocity during braking period.

d) None of the mentioned

Explanaton: ω(avg)=[ω()initial+ω(final)]/2.

7 - Question

A solid cast iron disk of mass 1000kg is rotating at 350rpm. Diameter of the disk is 1m and time taken to come to stop the disk by brake is 1.6sec.Square of radius of gyration is 0.2. Calculate the angle through which disk rotated during braking period.

Explanation: ω(avg)=[ω()initial+ω(final)]/2 and θ=ωt.

8 - Question

A solid cast iron disk of mass 1000kg is rotating at 350rpm. Diameter of the disk is 1m and time taken to come to stop the disk by brake is 1.6sec.Square of radius of gyration is 0.2. Calculate the torque capacity of the brake.

a) 812.4N-m
b) 4583.6N-m
c) 612.4N-m
d) Noe of the listed

Explanation: M=E/θ.

9 - Question

An automobile brake is only used to reduce the speed or bring the vehicle to hault.

a) Yes
b) No, it also be used to hold the car
c) Brake acts only onmoving vehicles
d) None of the mentioned