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प्रश्न
What are mechanical waves?
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उत्तर
The waves which travel in the medium through the vibrations of the medium particles about their mean positions are called mechanical waves.
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संबंधित प्रश्न
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.
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.

How do you tune your radio set to a particular station ? Name the phenomenon involved in doing so and define it.
In fig. , P, Q, R and S represent test tubes each of height 20 cm which are filled with water upto heights of 10 cm, 14 cm, 16 cm and 18 cm respectively. If a vibrating tuning fork is placed over the mouth of test tube Q, a loud sound is heard.
(i) Describe the observations with the tubes P, R and S.
(ii) Give the reason for your observation in each case.
(iii) State the principle illustrated by the above experiment.

Give two examples of forced vibrations.
What do you mean by resonance? When does resonance occur?
Explain why does the rear mirror of a motorbike start Vibrating Violently, at some particular speed of motorbike?
A vibrating tuning fork is placed over the mouth of a burette filled with water. The tap is opened and the water level gradually falls. It is observed that the sound becomes the loudest for a particular length of the air column. What is the name of the phenomenon taking place when this happens? Why does the sound become the loudest?
