Question

Name the phenomenon that causes a loud sound when the stem of a vibrating tuning fork is kept pressed on the surface of a table.

Answer 1

Hint: Recall that resonance occurs if any object or material vibrates. It is a phenomenon in which a vibrating system or an external force exerts force on the other system around it so that it can also vibrate with a greater amplitude at some specific frequency.

Complete solution:
The phenomenon which causes the loud sound is resonance. Due to resonance, the amplitude of the vibration of the sound wave increases. It also increases the intensity which further increases the loudness. The phenomenon of resonance occurs in all types of waves or vibrations such as: mechanical resonance, acoustic resonance and electromagnetic resonance.
If the stem of a vibrating tuning fork is pressed on the table, the force is applied by the tuning fork on the table. As a result the table will start vibrating at its own frequency. But the vibrations produced by the table are known as forced vibrations. So they have a greater energy and thus they produce a large sound.
But if the natural frequency of the table is equal to that of the frequency of the tuning fork, then resonance will occur. As a result, a loud sound will be produced.

Note: It is important to note that the word resonance comes from a Latin word which means to resound. Also the sound production in musical instruments is caused due to the phenomenon of resonance. In resonance, the vibration continues for some more time even after the external force is removed.