Natural and Forced Vibrations

Q.

“Resonance is a special case of forced vibration”. This is because

1. All forced vibrations are resonance vibrations

2. All resonance vibrations are forced vibrations

3. All natural vibrations are resonance vibrations

4. Resonance occurs only when a body is disturbed gently

5. Resonance occurs only when a body is disturbed violently

Q.

When a body vibrates under a periodic force, the vibration of the body is called:

1. natural vibration

2. damped vibration

3. forced vibration

4. resonant vibration

Q.

Choose the correct statements about 'Forced vibration':

1. There is a presence of external periodic force.
   

2. The frequency of vibration is equal to the frequency of the applied force.
   

3. The amplitude of vibration does not depend on the frequency of the applied force.
   

4. The frequency of vibration changes with a change in the frequency of the applied force.

Q.

When a tuning fork, struck by a rubber pad is held over a length of the air column in a tube, it produces a loud sound for a fixed length of the air column.
How does the frequency of the loud sound compare with that of the tuning fork?

Q.

What adjustments should you make for tuning stringed instruments to emit a note of desired frequency?

1. Changing the thickness of the string only

2. Changing the length of the string only

3. Changing the length, the tension of the string, and by using wire with different thickness

4. Changing tension of the wire, and by using string with different thickness

Q.

State which kind of vibrations (free, forced or resonant) are the following:

i) A tuning fork is struck against a rubber pad and its stem is held in hand.

ii) Two large tuning forks each of frequency 512 Hz with their stems fixed on wooden boxes are placed 1 m apart on a table. When one is set into vibrations the other too is observed to emit sound.

1. i) Resonant, ii) Forced

2. i) Forced, ii) Free

3. i) Free, ii) Resonant

4. i) Resonant, ii) Free

Q.

What is forced frequency?

Q.

The periodic vibrations of a body in the absence of any external force is called:

1. damped vibration

2. natural vibration

3. forced vibration

4. resonant vibration

Q.

When a body vibrates under a periodic force, the vibration of the body is called:

1. natural vibration

2. damped vibration

3. forced vibration

4. resonant vibration

Q. When a body vibrates under a periodic force, the vibrations of the body are:

Q.

Explain natural and forced vibrations with examples.

Q. Which of the following works on the principle of forced vibration?

1. Tuning fork
2. Drum
3. Guitar
4. All of the above

Q. While opening a tap with two fingers, the forces applied are

1. equal in magnitude
2. parallel to each other
3. opposite in direction
4. All of the above