Kinematics and Theory of Machines (3131906) MCQs

MCQs of Friction, Clutch and Brake

Showing 51 to 60 out of 77 Questions
51.

A body of weight W is required to move up the rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by _____.

(a)

P = W tanα

(b)

P = W tan (α + ɸ)

(c)

P = W (sinα + μ cosα)

(d)

P = W (cosα + μ sinα)

Answer:

Option (c)

52.

 In a screw jack, the effort required to lower the load W is given by _____.

(a)

P = W tan (α – ɸ)

(b)

P = W tan (α + ɸ)

(c)

P = W tan (ɸ – α)

(d)

P = W cos (α + ɸ)

Answer:

Option (c)

53.

The load cup of a screw jack is made separate from the head of the spindle to ______.

(a)

enhance the load carrying capacity of the jack

(b)

reduce the effort needed for lifting the working load

(c)

reduce the value of frictional torque required to be countered for lifting the load

(d)

prevent the rotation of load being lifted

Answer:

Option (d)

54.

The dynamic friction is the friction experienced by a body when the body ________.

(a)

is in motion

(b)

is at rest

(c)

just begins to slide over the surface of the other body

(d)

just ends to slide over the surface of the other body

Answer:

Option (a)

55.

A jaw clutch is essentially a _____ clutch.

(a)

positive action

(b)

cone

(c)

friction

(d)

disc

Answer:

Option (a)

56.

The material used for the lining of friction surfaces of a clutch should have _____________ coefficient of friction.

(a)

zero

(b)

low

(c)

medium

(d)

high

Answer:

Option (d)

57.

The torque developed by a disc clutch is given by ______.

(a)

T = 0.25 µ W R

(b)

T = 0.5 µ W R

(c)

T = 0.75 µ W R

(d)

T = µ W R

Answer:

Option (d)

58.

In a centrifugal clutch, the force with which the shoe presses against the driven member is the ___________ of the centrifugal force and the spring force.

(a)

difference

(b)

sum

(c)

ratio

(d)

multiplication

Answer:

Option (a)

59.

In the case of a multiple disc clutch, if n1 is the number of discs on the driving shaft and n2 is the number of the discs on the driven shaft, then the number of pairs of contact surfaces will be _______.

(a)

n1 + n2

(b)

n1 + n - 1

(c)

n1 + n + 1

(d)

n1 - n2

Answer:

Option (b)

60.

Which of the following is not true regarding the law of friction?

(a)

The force of solid friction is directly proportional to the normal reaction between the two surfaces s opposes the motion between the surfaces

(b)

The force of solid friction depends upon the materials of the two surfaces

(c)

The force of solid friction depends upon the area of contact

(d)

The force of solid friction is independent of the velocity of sliding

Answer:

Option (c)

Showing 51 to 60 out of 77 Questions