Dynamics of Machinery (3151911) MCQs

MCQs of Free vibrations and damped free vibrations

Showing 71 to 80 out of 88 Questions
71.

A shaft carrying two rotors will have

(a)

no node

(b)

one node

(c)

two nodes

(d)

three nodes

Answer:

Option (b)

72.

A shaft carrying three rotors will have

(a)

no node

(b)

one node

(c)

two nodes

(d)

three nodes

Answer:

Option (c)

73.

________ torsional vibrations will occur in a two-rotor system only if both rotors have the same frequency.

(a)

Free

(b)

Forced

(c)

Unbalanced

(d)

Balanced

Answer:

Option (a)

74.

In a two-rotor system, torsional vibration occurs only if the rotors are moving in the ______ direction.

(a)

same

(b)

opposite

(c)

either same or opposite

(d)

neither same nor opposite

Answer:

Option (b)

75.

Keeping the mass moment of inertia of both the shafts in a two-rotor system same, if the length of one shaft is doubled what should be the effect on the length of another shaft?

(a)

Doubled

(b)

Halved

(c)

Constant

(d)

Increased to 4 times

Answer:

Option (a)

76.

For a two-rotor system, the length of one shaft (A) is twice the shaft (B), then what is the relation between the mass moment of inertia of the shafts?

(a)

2I(A) = I(B)

(b)

I(A) =2I(B)

(c)

I(A) = I(B)

(d)

2I(A) = 3I(B)

Answer:

Option (a)

77.

For a two-rotor system, the mass moment of inertia of one shaft (A) is twice the other (B), then what is the relation between the length of the shafts?

(a)

2L(A) = L(B)

(b)

L(A) = 2L(B)

(c)

L(A) = L(B)

(d)

2L(A) = 3L(B)

Answer:

Option (a)

78.

In which of the following condition torsional vibration will not take place, considering 3 rotors A, B and C. A is rotating in the clockwise direction.

(a)

B in clockwise C in anticlockwise

(b)

C in clockwise B in anticlockwise

(c)

B and C in clockwise

(d)

B and C in anticlockwise

Answer:

Option (c)

79.

For the occurrence of free torsional vibration in a three-rotor system which of the condition is necessary?

(a)

Rotors moving in the same direction

(b)

Rotors having the same frequency

(c)

Rotors having different frequency

(d)

Rotors rotate in the same sense

Answer:

Option (b)

80.

What is the total number of nodes formed in a three-rotor system if the rotors at one of the ends and the one in the middle rotate in the same direction?

(a)

0

(b)

1

(c)

2

(d)

3

Answer:

Option (b)

Showing 71 to 80 out of 88 Questions