Advertisements
Advertisements
प्रश्न
In the diagram below, A, B, C, D are four pendulums suspended from the same elastic string PQ. The length 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
1) Name the type of vibrations taking place in pendulums B and D?
2) What is the state of pendulum C?
3) State the reason for the type of vibrations in pendulum B and C.
Advertisements
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
APPEARS IN
संबंधित प्रश्न
The diagram above shows a wire stretched over a sonometer. Stems of two vibrating tuning forks A and Bare touched to the wooden box of the sonometer. It is observed that the paper rider (a small piece of paper folded at the centre) present on the wire flies off when the stem of vibrating tuning fork B is touched to the wooden box but the paper just vibrates when the stem of vibrating tuning fork A is touched to the wooden box.
1) Name the phenomenon when the paper rider just vibrates.
2) Name the phenomenon when the paper rider flies off.
3) Why does the paper rider fly off when the stem of tuning fork B is touched to the box?
Describe a simple experiment to illustrate the phenomenon of resonance and explain it.
A tuning fork of frequency 256 Hz will resonate with another tuning fork of frequency:
(i) Define resonant vibrations.
(ii) Which characteristic of sound, makes it possible to recognize a person by his voice without seeing him?
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).
On keeping the stem of a vibrating tuning fork on the surface of a table, a loud sound is heard. Give reason.
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?
