Theory Of Machine MCQ Questions & Answers

21

The equation of free vibrations of a system is $$\frac{{{{\text{d}}^2}{\text{x}}}}{{{\text{d}}{{\text{t}}^2}}} + 36{\pi ^2}{\text{x}} = 0{\text{,}}$$ its natural frequency is

A) 3Hz B) $$3\pi {\text{Hz}}$$ C) 6Hz D) $$6\pi {\text{Hz}}$$

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

22

A rotor supported at A and B carries two masses as shown in the below figure. The rotor is
Theory of Machine mcq question image

A) Dynamically balanced B) Statically balanced C) Statically and dynamically balanced D) Not balanced

Discuss

Answer & Solution

Answer: Option C

Solution:

23

According to Kennedy's theorem, if three bodies have plane motions, their instantaneous centers lie on

A) A triangle B) A point C) Two lines D) A straight line

Discuss

Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board

24

The amplitude of vibration is always __________ the radius of the circle.

A) Equal to B) Less than C) Greater than D) None of these

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

25

The Bifilar suspension method is used to determine

A) Natural frequency of vibration B) Position of balancing weights C) Moment of inertia D) Centripetal acceleration

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

26

Under logarithmic decrement, the amplitude of successive vibrations are

A) Constant B) In arithmetic progression C) In geometric progression D) In logarithmic progression

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

27

At the nodal point in a shaft, the amplitude for torsional vibration will be

A) Minimum B) Maximum C) Zero D) Infinity

Discuss

Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

28

In a multiple V-belt drive, if one of the belts is broken, then we should replace

A) The broken belt only B) All the belts C) The broken belt and the belts on either side of it D) None of the above

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

29

The displacement of the reciprocating roller follower, when it has contact with the straight flanks of the tangent cam, is given by (where r₁ = Minimum radius of the cam, r₂ = Radius of the roller follower and $$\theta $$ = Angle turned by the cam from the beginning of the follower displacement)

A) $$\left( {{{\text{r}}_1} - {{\text{r}}_2}} \right)\left( {1 - \cos \theta } \right)$$ B) $$\left( {{{\text{r}}_1} + {{\text{r}}_2}} \right)\left( {1 + \cos \theta } \right)$$ C) $$\left( {{{\text{r}}_1} - {{\text{r}}_2}} \right)\left( {\frac{{1 - \cos \theta }}{{\cos \theta }}} \right)$$ D) $$\left( {{{\text{r}}_1} + {{\text{r}}_2}} \right)\left( {\frac{{1 - \cos \theta }}{{\cos \theta }}} \right)$$

Discuss

Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board

30

A flywheel is fitted to the crankshaft of an engine having W as the amount of indicated work per revolution and permissible limits of coefficient of fluctuation of energy and speed as C_E and C_S respectively. The kinetic energy of the flywheel is given by

A) $$\frac{{2{\text{W}}{{\text{C}}_{\text{E}}}}}{{{{\text{C}}_{\text{S}}}}}$$ B) $$\frac{{{\text{W}}{{\text{C}}_{\text{E}}}}}{{{\text{2}}{{\text{C}}_{\text{S}}}}}$$ C) $$\frac{{{\text{W}}{{\text{C}}_{\text{E}}}}}{{{{\text{C}}_{\text{S}}}}}$$ D) $$\frac{{{\text{W}}{{\text{C}}_{\text{S}}}}}{{{\text{2}}{{\text{C}}_{\text{E}}}}}$$

Discuss

Answer & Solution

Answer: Option B

No explanation is given for this question. Let's Discuss on Board

Theory Of Machine MCQ Questions & Answers | Mechanical Engineering