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प्रश्न
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उत्तर
When an oscillatory system is made to oscillate under the action of an externally applied periodic force, it is said to execute forced vibrations. In this case the external frequency may or may not be equal to the natural frequency of the body.
In case of resonance, the externally applied periodic force has the same frequency as the natural frequency of oscillation of the given oscillatory system.
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संबंधित प्रश्न
What are forced vibrations?
Give one example to illustrate forced vibrations.
In following figure shows A, B , C and D represent test tube each of height 20 cm which are filled with water up to heights of 12 cm, 14 cm, 16cm and 18cm respectively. If a vibrating tuning fork is placed over the mouth if test tube D, a loud sound is heard.
- Describe the observations with the tubes A, B and C when the vibrating tuning fork is placed over the mouth of these tubes.
- Give the reason for your observation in each case.
- State the principle illustrated by the above experiment.
(i) Define resonant vibrations.
(ii) Which characteristic of sound, makes it possible to recognize a person by his voice without seeing him?
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.
On keeping the stem of a vibrating tuning fork on the surface of a table, a loud sound is heard. Give reason.
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. Name the above phenomenon. How does the frequency of the loud sound compare with that of the tuning fork? State the unit for measuring loudness.
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 free vibrations of a body? Draw a displacement-time graph to represent them. Given one example.
