Engineering Mechanics

Question: In a wormed geared pulley block, if the number of teeth on the worm wheel is doubled, then its velocity ratio is also doubled.
[A].

True

[B].

False

Answer: Option A

Explanation:

No answer description available for this question.

Question: In a single threaded worm and worm wheel, the number of teeth on the worm is 50. The diameter of the effort wheel is 100 mm and that of load drum is 50 mm. The velocity ratio is
[A].

50

[B].

100

[C].

150

[D].

200

Answer: Option B

Explanation:

No answer description available for this question.

Question: A differential pulley block has larger and smaller diameters of 100 mm and 80 mm respectively. Its velocity ratio is
[A].

5

[B].

10

[C].

20

[D].

40

Answer: Option B

Explanation:

No answer description available for this question.

Question: If the number of pulleys in a system is equal to its velocity ratio, then it is a __________ system of pulleys
[A].

first

[B].

second

[C].

third

Answer: Option B

Explanation:

No answer description available for this question.

Question: For a self locking machine, the efficiency must be
[A].

equal to 50%

[B].

less than 50%

[C].

greater than 50%

[D].

100%

Answer: Option B

Explanation:

No answer description available for this question.

Question: A weight of 1000 N can be lifted by an effort of 80 N. If the velocity ratio is 20, the machine is
[A].

reversible

[B].

non-reversible

[C].

ideal

Answer: Option A

Explanation:

No answer description available for this question.

Question: A screw jack used for lifting the loads is
[A].

a reversible machine

[B].

a non-reversible machine

[C].

an ideal machine

[D].

none of these

Answer: Option B

Explanation:

No answer description available for this question.

Question: A non-reversible machine is also called a self-locking machine.
[A].

Agree

[B].

Disagree

Answer: Option A

Explanation:

No answer description available for this question.

Question: A machine which is not capable of doing any work in the reversed direction, after the effort is removed, is called a reversible machine.
[A].

True

[B].

False

Answer: Option B

Explanation:

No answer description available for this question.

Question: If the resultant of two equal forces has the same magnitude as either of the forces, then the angle between the two forces is
[A].

30°

[B].

60°

[C].

90°

[D].

120°

Answer: Option D

Explanation:

No answer description available for this question.