SECTION-6

#### Theory of Machine objective type questions/Multiple choice questions

##### Q71. The smallest circle drawn to the cam profile from the cam centre is known as

(a) prime circle
(b) base circle
(c) pitch circle
(d) pitch curve.

Ans:  (b) base circle

##### Q72. The smallest circle drawn to the pitch curve from the centre of rotation of the cam is known as

(a) prime circle
(b) base circle
(c) pitch circle
(d) none of the above.

Ans:  (a) prime circle

##### Q73. The point, on the cam pitch curve having the maximum pressure angle, is called

(a) the pitch point
(b) the trace point
(c) the centre of cam
(d) none of the above.

Ans:  (a) the pitch point

##### Q74. The pressure angle of a cam is the angle at any point on the pitch curve.

(a) made by line of motion of the follower with horizontal axis
(b) made by line of motion of the follower with vertical axis
(c) between the normal to that point on the curve and line of motion of follower at that instant
(d) between the tangent to that point on the curve and line of motion of follower at that instant.

Ans:  (c) between the normal to that point on the curve and line of motion of follower at that instant

##### Q75. The angle, which represents the cam profile and is most important in cam design, is

(a) cam angle
(b) pressure angle
(c) angle of dwell
(d) angle of descent.

Ans:  (b) pressure angle

##### Q76. The stroke of the follower is equal to

(a) half of the maximum travel of the follower from the lowest position to the topmost position
(b) the maximum travel of the follower from the lowest position of the topmost position
(c) half of the diameter of base circle
(d) half of the diameter of the prime circle.

Ans:  (b) the maximum travel of the follower from the lowest position of the topmost position

##### Q77. A roller follower, the diameter 30 mm, is in contact with the straight flask of a tangent cam of base circle diameter 70 mm. The cam has rotated through 30° when the roller is just to leave contact of the flank on its ascent. If the angular speed of the cam is 10 rad/sec, then left the roller, when it is just to leave contact of the flank will be

(a) 10 mm
(b) 7.73 mm
(c) 5 mm
(d) 4 mm.

Ans:  (b) 7.73 mm

##### Q78. The height of a Watt’s governor is

(a) inversely proportional to speed
(b) inversely proportional to square of speed
(c) directly proportional to speed
(d) directly proportional to square of speed.

Ans:  (b) inversely proportional to square of speed

##### Q79. The angular speed of a Watt’s governor, when its height is 20 cm, will be equal to

Ans:  (d) 7 rad/sec.

##### Q80. A vibrating body is said to be number the action of damping when

(a) the amplitude of the body gradually increases with time
(b) the amplitude of the body is constant with respect to time
(c) the amplitude of the body gradually decreases with time
(d) none of the above.

Ans:  (c) the amplitude of the body gradually decreases with time

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##### Read More Sections of Theory of Machine Objective Questions

Each section contains maximum 80 Questions. To practice more questions visit other sections.

Theory of Machine MCQ – Section-1

Theory of Machine MCQ – Section-2

Theory of Machine MCQ – Section-3

Theory of Machine MCQ – Section-4

Theory of Machine MCQ – Section-5

Theory of Machine MCQ – Section-6