Natural Vibration

Q.

What is meant by the natural frequency of vibrations of a body ? Name one factor on which it depends.

Q.

How does the medium affect the amplitude of the natural vibrations of a body ?

Q.

What are the essential properties a medium must possess for the propagation of mechanical waves?

1. Stable pressure

2. Maximum friction

3. Constant temperature

4. Minimum friction

Q.

(a) Draw a graph between displacement and time for a body executing the natural vibrations.

(b) Where can a body execute the natural vibrations ?

Q.

State one condition for a body to execute the natural vibrations.

Q.

What do you understand by the natural vibrations of a body ? Give one example.

Q.

The frequency of damped vibrations remains same (constant )? And what are the "applications " of damped vibrations (as given in the icse syllabus)?

Q.

What is resonance frequency?

Q.

A wire of length 80 cm under some tension produces a sound of frequency 256 Hz. What length of wire will produce the sound of frequency 1024 Hz under the same tension?

1. 18 cm
   

2. 20 cm

3. 15 cm
   

4. 10 cm
   

Q.

A wire stretched between the two fixed supports, is plucked exacly in the middle and then released. It executes (neglect the resistance of the medium) :

(a) resonant vibrations (b) natural vibrations

(c) damped vibrations (d) forced vibrations.

Q.

A wire of length 80 cm under some tension produces sound of frequency 256 Hz. What length of wire will produce sound of frequency 1024 Hz under same tension?

1. 10cm
   

2. 15cm
   

3. 18cm
   

4. 20cm

Q.

What is the difference between natural frequency and resonant frequency?

Q. State the condition for the occurrence of resonance.

Q.

Give one example each of natural vibration, forced vibration and resonance.

Q. What is meant by natural frequency of vibration of a body ?

Q. What happens when the frequency of externally applied force becomes equal to the natural frequency of the body on which the force is applied?

1. The amplitude of resonance remains constant with time.
2. The body starts resonating.
3. The body resonates with a higher amplitude.
4. All of the above.

Q. Among the given options, which are the examples of simple harmonic motion?

1. Oscillation of simple pendulum.
2. A tuning fork which is hit against a rubber pad.
3. The load attached to the lower end of a spring suspended from a support is pulled and released.
4. All of the above.

Q. A particle of mass 0.10 kg executes Simple harmonic motion with an amplitude 0.05 m and frequency 20 vib/s. Its energy of oscillation is

1. 1 J
2. 2 J
3. 4 J
4. zero

Q.

What is the amplitude of a wave?

Q.

In forced oscillation of a particle the amplitude is maximum for a frequency ω₁ of force, while the energy Is maximum for a frequency ω₂ of the force, then:

1. ω1 > ω2

2. ω1 < ω2

3. ω1 = ω2

4. None f these.

Q. Distinguish between the free(or natural) and forced vibrations.

Q. What do you understand by free vibrations of a body? Give one example.

Q. What to you understand by free vibrations of a body?

Q. When a liquid is heated in a glass vessel, its coefficient of apparent expansion is $1.03\times {10}^{-3}/{}^{\circ }C$. When the same liquid is heated in a copper vessel, its coefficient of apparent expansion is $1.006\times {10}^{-3}/{}^{\circ }C$. If the coefficient of linear expansion of copper is $17\times {10}^{-6}/{}^{\circ }C$, then the coefficient of linear expansion of glass is:

1. $9\times {10}^{-6}/{}^{\circ }C$
2. $27\times {10}^{-6}/{}^{\circ }C$
3. $8.5\times {10}^{-4}/{}^{\circ }C$
4. $10\times {10}^{-4}/{}^{\circ }C$

Q.

The co-efficient of real expansion of liquid is ${\gamma }_r$ and the co-efficient of apparent expansions of the liquid is ${\gamma }_a$. The co-efficient of cubical expansion of the vessel is $\gamma$. If ${\gamma }_r:{\gamma }_a=4:1$ then ${\gamma }_a:\gamma$ is :

1. 4:1
2. 3:1
3. 1:3
4. 1:4

Q.

The co-efficient of real expansion ${\gamma }_r$ of a liquid is 5 times the co-efficient of linear expansion of the material of the container in which the liquid is present. The ratio of the co-efficient of apparent expansion and real expansion of the liquid is:

1. $5:2$
2. $1:5$
3. $5:1$
4. $2:5$

Q. A transverse wave is passing through a medium. The maximum speed of the vibrating particle occurs when the displacement of the particle from the mean position is

1. zero
2. half of the amplitude
3. equal to the amplitude
4. none of the above

Q. The motion of a vehicle suspension system just after the vehicle encounters a pothole is an example of

1. damped vibration
2. forced vibration
3. natural vibration
4. None of these

Q.

If $\gamma$ (apparent) of a liquid in a vessel is $76$% of $\gamma$ (real) of that liquid, the coefficient of linear expansion of the vessel is

1. $24$% of $\gamma$ (real)
2. $8$% of $\gamma$ (real)
3. $16$% of $\gamma$ (real)
4. $25.3$% of $\gamma$ (real)

Q. Differentiate between free and forced vibrations.