Advertisements
Advertisements
Question
What do you understand by free (or natural) vibrations?
Advertisements
Solution
Any object when slightly disturbed from its position of rest or equilibrium vibrates with its own period irrespective of its size or shape, is said to make vibrations. The time period of said vibrations is called natural time period and the frequency is called natural frequency. In the absence of any resistance such as air, the amplitude of free vibration remains constant.
RELATED QUESTIONS
In following figure shows two tuning forks A and B of the same frequency mounted on two separate sound boxes with their open ends facing each other. The fork A is set into vibration.
- Describe your observation.
- State the principle illustrated by this experiment.

When a troop crosses a suspension bridge, the soldiers are asked to break steps. Explain the reason.
How do you tune your radio set to a particular station ? Name the phenomenon involved in doing so and define it.
When a body vibrates under a periodic force, the vibrations of the body are ______.
Two pendulums C and D are suspended from a wire as shown in the figure give below. Pendulum C is made to oscullate by displaying it from its mean position. It is seen that D also starts oscillating.

(i) Name the type of oscillation, C will execute.
(ii) Name the type of oscillation, D will execute.
(iii) If the length of D is made equal to C then what difference will you notice in the oscillations of D ?
(iv) What is the name of the phenomenon when the length of D is made equal to C ?
In fig. shows two tuning forks P and Q of the same frequency mounted on separate sound boxes with their open ends facing each other. The fork A is set into vibration. (i) Describe your observation. (ii) State the principle illustrated by this experiment.

In Fig. A, B, C and D are four pendulums suspended from the same elastic string XY. The lengths of pendulum A and D are equal, while the length of pendulum B is shorter and of the pendulum C is longer. Pendulum A is set into vibrations.

- What is your observation about the vibrations of pendulum D?
- Give reason for your observation in part (a).
- What type of vibrations take place in pendulums Band C?
- Give reason for the answer in part (c).
The diagram below shows three different modes of vibration P, Q and R of the same string of a given length.
![]() |
![]() |
![]() |
| P | Q | R |
- Which vibration will produce a louder sound and why?
- Which vibration will produce sound of maximum shrillness (or pitch) and why?
- What is the ratio of wavelength of vibrations P and R?
Explain why does the rear mirror of a motorbike start Vibrating Violently, at some particular speed of motorbike?
What do you understand by free vibrations of a body? Draw a displacement-time graph to represent them. Given one example.



