Kinematics and Theory of Machines (3131906) MCQ

MCQs of Friction, Clutch and Brake

MCQ No - 1

The angle of inclination of the plane, at which the body begins to move down the plane, is called ________.

(A)

angle of friction

(B)

angle of repose

(C)

angle of projection

(D)

helix angle


A
MCQ No - 2

In a screw jack, the effort required to lift the load W is given by _____ where α is helix angle and Φ is the angle of friction.

(A)

$$\mathrm P=\mathrm W\times\tan\;(\mathrm\alpha-\mathrm\phi)$$

(B)

$$\mathrm P=\mathrm W\times\tan\;(\mathrm\alpha+\mathrm\phi)$$

(C)

$$\mathrm P=\mathrm W\times\cos\;(\mathrm\alpha-\mathrm\phi)$$

(D)

$$\mathrm P=\mathrm W\times\cos\;(\mathrm\alpha+\mathrm\phi)$$


B
MCQ No - 3

The efficiency of a screw jack is given by _______.

(A)

$$\frac{\tan\;(\mathrm\alpha+\mathrm\phi)}{\tan\;\mathrm\alpha}$$

(B)

$$\frac{\tan\;\mathrm\alpha}{\tan\;(\mathrm\alpha+\mathrm\phi)}$$

(C)

$$\frac{\tan\;(\mathrm\alpha-\mathrm\phi)}{\tan\;\mathrm\alpha}$$

(D)

$$\frac{\tan\;\mathrm\alpha}{\tan\;(\mathrm\alpha-\mathrm\phi)}$$


B
MCQ No - 4

The radius of a friction circle for a shaft of radius r rotating inside a bearing is ______.

(A)

$$\mathrm r\times\mathrm{sin}\;\mathrm\phi$$

(B)

$$\mathrm r\times\mathrm{cos}\;\mathrm\phi$$

(C)

$$\mathrm r\times\mathrm{tan}\;\mathrm\phi$$

(D)

$$\mathrm r\times\mathrm{cot}\;\mathrm\phi$$


A
MCQ No - 5

The efficiency of a screw jack is maximum when _______.

(A)

$$\mathrm\alpha=45^\circ+\frac{\mathrm\phi}2$$

(B)

$$\mathrm\alpha=45^\circ-\frac{\mathrm\phi}2$$

(C)

$$\mathrm\alpha=90^\circ+\mathrm\phi$$

(D)

$$\mathrm\alpha=90^\circ-\mathrm\phi$$


B