Dynamics of Machinery (3151911) MCQs

MCQs of Free vibrations and damped free vibrations

Showing 51 to 60 out of 88 Questions
51.

A certain amount of energy possessed by the vibrating system is always dissipated in overcoming __________ to the motion.

(a)

fluid resistances

(b)

thermal resistances

(c)

frictional resistances

(d)

air resistances

Answer:

Option (c)

52.

The unit of the damping factor is ______.

(a)

Nm/s

(b)

N/sm

(c)

N/m

(d)

none of the mentioned

Answer:

Option (d)

53.

The unit of the damping coefficient is ______.

(a)

N/sm

(b)

N/m/s

(c)

N/m

(d)

Nm

Answer:

Option (b)

54.

Calculate mass from the following data: critical damping coefficient= 6283 N/m/s and ω = 10 rad/s.

(a)

50 kg

(b)

75 kg

(c)

100 kg

(d)

125 kg

Answer:

Option (c)

55.

Calculate critical damping coefficient in N/m/s from the following data: mass = 100 Kg and ω = 40rad/s.

(a)

25132

(b)

26132

(c)

27132

(d)

28132

Answer:

Option (a)

56.

A system has a mass of 600 Kg has a spring of stiffness 294000 N/m. What will be the value of the critical damping coefficient?

(a)

16563

(b)

26563

(c)

36563

(d)

46563

Answer:

Option (b)

57.

A gun barrel of mass 600 Kg has a recoil spring of stiffness 294 KN/m. If the barrel recoils 1.3 m on firing, what will be the initial recoil velocity of the barrel?

(a)

28.77 m/s

(b)

32.77 m/s

(c)

35.77 m/s

(d)

40.77 m/s

Answer:

Option (a)

58.

The damping factor is the measure of the relative amount of damping in the existing system with that necessary for the ______ system.

(a)

underdamped

(b)

overdamped

(c)

critical damped

(d)

all of the mentioned

Answer:

Option (c)

59.

In which of the following cases, critical damping occurs?

(a)

Roots are real

(b)

Roots are complex conjugate

(c)

Roots are equal

(d)

Independent of the equation

Answer:

Option (c)

60.

In which of the following cases, under damping occurs?

(a)

Roots are real

(b)

Roots are complex conjugate

(c)

Roots are equal

(d)

Independent of the equation

Answer:

Option (b)

Showing 51 to 60 out of 88 Questions