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प्रश्न
Explain free and forced vibrations. Give an experimental arrangement to illustrate the phenomenon of resonance.
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उत्तर
When a system or a body vibrates without receiving impulses from another system or body, its vibrations are said to be free vibrations. However, when a system or body vibrates on account of impulses received from another system or body, the vibrations are called forced vibrations. In such a case the body or the system vibrates with the frequency of the impulses received and not with its natural frequency.
Experiment Arrangement to illustrate Resonance: In the figure, the two pendulums have exactly equal lengths. However, the bob of the pendulum A is heavier. Displace the bob of the pendulum A by a little distance in a direction perpendicular to the plane containing the two pendulums. Then release the bob. The pendulum A will begin to oscillate. After a short while, you will find that the pendulum B also begins to vibrate. Note that the two pendulums have the same frequency. The pendulum A through the rubber tube applies impulses of the same frequency on the pendulum B Hence, the pendulum B begins to vibrate.
संबंधित प्रश्न
Give one example to illustrate forced vibrations.
Describe a simple experiment to illustrate the phenomenon of resonance and explain it.
A vibrating tuning fork, held over an air column of a given length with its one end closed, produces a loud audible sound. Name the phenomenon responsible for it and explain the observation.
Why are the stringed instruments like guitar provided with a hollow sound box?
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).
Differentiate between the following:
Radio waves and light waves.
State two ways in which resonance differs from forced vibrations.
The rearview mirror of a motorbike starts vibrating violently at some particular speed of the motorbike. What is the name of the phenomenon taking place? Why does the happen?
When the stem of vibrating tuning fork is pressed on a table, the tabletop starts vibrating. These vibrations are definitely an example of ______.
