Advertisements
Advertisements
प्रश्न
Explain a tuning fork (vibrating) is held close to ear. One hears a faint sound. The same vibrating tuning fork is placed on table, such that its handle is in contact with table, one hears a loud sound.
Advertisements
उत्तर
When the tuning fork is held close to ear, then small amount of air is disturbed and hence sound is faint. When the handle of the vibrating tuning fork is held aganist table, it makes the table top to vibrate, with forced vibrations. As the table top has a larger surface area, therefore large volume of air is set into vibrations, thereby producing a loud sound.
संबंधित प्रश्न
What are mechanical waves?
The adjacent diagram shows three different modes of vibrations P, Q and R of the same string.

(i) Which vibration will produce a louder sound and why?
(ii) The sound of which string will have maximum shrillness?
(iii) State the ratio of wavelengths of P and R.

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?
Distinguish between the free (or natural) and forced vibrations.
Resonance is a special case of ______ vibrations, when frequency of the driving force is ______ natural frequency of the body.
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.

Explain why does the rear mirror of a motorbike start Vibrating Violently, at some particular speed of motorbike?
What do you understand by free (or natural) vibrations?
Explain free and forced vibrations. Give an experimental arrangement to illustrate the phenomenon of resonance.
