The transmissibility, for all values of damping factor, will be less than unity, if $$\frac{\omega }{{\omega {\text{n}}}}$$ is

In vibration isolation system, the transmissibility will be equal to unity, for all values of damping factor, if $$\frac{\omega }{{\omega {\text{n}}}}$$ is

A

Equal to 1

B

Equal to 2

C

Less than 2

D

Greater than 2

The raised cosine pulse p(t) is used for zero ISI in digital communications. The expression for p(t) with unity roll-off factor is given by $$p\left( t \right) = \frac{{\sin 4\pi \omega t}}{{4\pi \omega t\left( {1 - 16{\omega ^2}{t^2}} \right)}}.$$ The value of p(t) at $$t = \frac{1}{{4\omega }}$$ is

A

-0.5

B

0

C

0.5

D

∞

Two monochromatic waves having frequencies $$\omega $$ and $$\omega + \Delta \omega \left( {\Delta \omega \ll \omega } \right)$$ and corresponding wavelengths $$\lambda $$ and $$\lambda - \Delta \lambda \left( {\Delta \lambda \ll \lambda } \right)$$ of same polarization, travelling along X-axis are superimposed on each other. The phase velocity and group velocity of the resultant wave are respectively given by

A

$$\frac{{\omega \lambda }}{{2\pi }},\,\frac{{\Delta \omega {\lambda ^2}}}{{2\pi \Delta \lambda }}$$

B

$$\omega \lambda ,\,\frac{{\Delta \omega {\lambda ^2}}}{{\Delta \lambda }}$$

C

$$\frac{{\omega \Delta \lambda }}{{2\pi }},\,\frac{{\Delta \omega \Delta \lambda }}{{2\pi }}$$

D

$$\omega \Delta \lambda ,\,\omega \Delta \lambda $$

Which of the following methods are used for producing damping torque in analog instruments? 1) Air friction damping 2) Fluid friction damping 3) Eddy current damping 4) Electromagnetic damping

A

1, 2 and 3 only

B

1, 2 and 4 only

C

1, 3 and 4 only

D

1, 2, 3 and 4

From the given table, what is the percentage of students scoring 40 or more, but less than 70. Scores Less than 20 Less than 30 Less than 40 Less than 50 Less than 60 Less than 70 Less than 80 No. of Students 12 19 22 31 38 46 50

A

8%

B

56%

C

48%

D

96%

If $$\frac{\omega }{{\omega {\text{n}}}} = 2,$$ where co is the frequency of excitation and $${\omega {\text{n}}}$$ is the natural frequency of vibrations, then the transmissibility of vibration will the

A

0.5

B

1

C

1.5

D

2

If the damping factor is less than the damping factor at critical damping, the time response of the system is ___________

A

Underdamped

B

Overdamped

C

Marginally damped

D

Unstable

From the following table, how many patients were in the age group 40 – 60? Age (years) Less than 10 Less than 20 Less than 30 Less than 40 Less than 50 Less than 60 Less than 70 No. of patients 11 15 22 29 35 45 50

A

6

B

16

C

45

D

29

In vibration isolation system, if ω/ωn is less than √2 , then for all values of the damping factor, the transmissibility will be

A

less than unity

B

equal to unity

C

greater than unity

D

zero where ω = Circular frequency of the system in rad/s, and ωn = Natural circular frequency of vibration of the system in rad/s.

If 30Ω6 = -5, 80Ω2 = -40 and 20Ω4 = -5, then find the value of 70Ω2 = ?

A

10

B

-35

C

15

D

-20

The transmissibility, for all values of damping factor, will be less than unity, if $$\frac{\omega }{{\omega {\text{n}}}}$$ is

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