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प्रश्न
In the diagram below, A, B, C, D are four pendulums suspended from the same elastic string PQ. The lengths of A and C are equal to each other, while the length of pendulum B is smaller than that of D. Pendulum A is set into a mode of vibrations.
- Name the type of vibrations taking place in pendulums B and D.
- What is the state of pendulum C?
- State the reason for the type of vibrations in pendulums B and C.
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उत्तर
1) The vibrations which occur in pendulums B and D are called forced vibrations.
2) Pendulum C is in the state of resonance with pendulum A as it is of the same length.
3) The pendulums vibrate because the forced vibration from A is transferred due to string PQ.
Pendulum B is of a different length as compared to pendulum A. Hence, it will continuously vibrate with a frequency which is different from that of pendulum A. Its amplitude will also be very small.
Pendulum C is of the same length as compared to pendulum A. Hence, it will vibrate in phase with pendulum A. Its amplitude will be equal to that of pendulum A, as it will attain resonance.
संबंधित प्रश्न
Distinguish between the free (or natural) and forced vibrations.
Describe a simple experiment to illustrate the phenomenon of resonance and explain it.
In following figure shows A, B, C and D are four pendulums suspended from the same elastic string XY. Lengths of pendulum A and D are equal, while the length of pendulum B is smaller and the pendulum C is longer. The pendulum A is set into vibration.
(a) what is your observation? (b) Give reason for your observation.
Why are the stringed instruments like guitar provided with a hollow sound box?
Differentiate between the following:
Free and forced vibrations.
Explain a person walking past a railway line, in the middle of night hears a ringing sound along with the sound of his footsteps.
A string stretched between its ends is made to vibrate by placing the stem of a vibrating tuning fork at its one end. State three ways how you will increase the frequency of note produced by the string.
What do you understand by forced vibrations?
