If ω/ωn = root 2, where ω is frequency of excitation and ωn is natural frequency of vibrations, then transmissibility of vibrations will be

1.  0.5

2.  1.0

3.  1.5

4.  2.0

4
Correct Answer :

1.0

Explanation :
No Explanation available for this question

A slender shaft supported on two bearings at its ends carries a disc with an eccentricity e from the axis of rotation. The critical speed of the shafts is N. If the disc is replaced by a second one of same weight but mounted with an eccentricity 2e, critical speed of the shaft in the second case is

1.  N/2

2.  N/√2

3.  N

4.  2N

4
Correct Answer :

N

Explanation :
No Explanation available for this question

Whirling speed of a shaft coincides with the natural frequency of its

1.  Longitudinal vibration

2.  Transverse vibration

3.  Torsional vibration

4.  Coupled bending torsional vibration

4
Correct Answer :

Transverse vibration

Explanation :
No Explanation available for this question

When a shaking force is transmitted through the springs, damping becomes detrimental when the ratio of its frequency to the natural frequency is greater than

1.  0.25

2.  0.50

3.  1.00

4.  √2

4
Correct Answer :

√2

Explanation :
No Explanation available for this question

When the mass of a critically damped single degree of freedom system is deflected from its equilibrium position and released, it will

1.  Return to equilibrium position without oscillation

2.  Oscillate with increasing time period

3.  Oscillate with decreasing amplitude

4.  Oscillate with constant amplitude

4
Correct Answer :

Return to equilibrium position without oscillation

Explanation :
No Explanation available for this question

The equation of motion for a single degree of freedom system with viscous damping 4x + 9x +16x = 0. The damping ratio of the system is

1.  9/128

2.  9/16

3.  9/8√2

4.  9/8

4
Correct Answer :

9/16

Explanation :
No Explanation available for this question

For the spring mass system shown in the given figure, the frequency of oscillations of the block along the axis of the spring is

1.

2.

3.

4.

4
Correct Answer :

Explanation :
No Explanation available for this question

High damping reduces the transmissibility if the non-dimensional frequency ratio ω/ωn (ω = forcing frequency, ωn = natural frequency), is

1.  Less than √2

2.  Greater than root 2

3.  Less than 1/√2

4.  Greater than 1/√2

4
Correct Answer :

Less than √2

Explanation :
No Explanation available for this question

For lightly damped heavy rotor systems, resonance occurs when the forcing ω is equal to Where ωcr is critical speed

1.  2 ωcr

2.  Root 2 ωcr

3.  ωcr

4.  ωcr/2

4
Correct Answer :

ωcr

Explanation :
No Explanation available for this question

A machine mounted on a single coil spring has a period of free vibration of T. If the spring is cut into four equal parts and placed in parallel and the machine is mounted on them, then the period of free vibration of the new system will become

1.  16T

2.  4T

3.  T/4

4.  T/16

4
Correct Answer :

T/4

Explanation :
No Explanation available for this question

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