Question

(i) Name the phenomenon involved in tuning a radio set to a particular station.
(ii) Define the phenomenon named by you in part (i) above.
(iii) What do you understand by loudness of sound?
(iv) In which units is the loudness of sound measured?

Answer 1

(i) The phenomenon involved in tuning a radio set to a particular station is resonance.
(ii) Resonance is a condition of forced vibrations. When the frequency of an externally applied periodic force on a body is equal to its natural frequency, the body readily begins to vibrate with an increased amplitude. This phenomenon is known as resonance.
(iii) Loudness is the property by virtue of which a loud sound can be distinguished from a faint one, both having same pitch and frequency. Loudness of sound depends on amplitude of the wave.
(iv) The loudness of sound is measured in the unit decibels (dB).