Question

On which of the following does pitch depend?
(a). Wavelength
(b). Frequency
(c). Amplitude
(d). Periodicity and regularity

Answer 1

- Hint: Pitch of a sound tells about the shrillness of the sound. We often say that a nice voice is melodious or the voice is at high pitch. Think whether the shrillness or pitch depends on wavelength, frequency or amplitude i.e. loudness of the voice.

Complete step-by-step solution -

When a singer sings, we say that at some part the pitch is low or at some part the pitch is higher. Actually, what we are talking about is the frequency of the sound in the song. Frequency is the number of complete vibrations or cycles that take place in one second. So, if the vibrations are faster, meaning if the particle vibrates faster, the frequency is high and if the particle vibrates slowly, the frequency is low. If the frequency is higher, we say the pitch is high and if the frequency of the sound is low, we say the pitch is lower.
We even say that the girls’ voice has higher pitch than that of the boys. This is because girls have shorter vocal cords than boys. The shorter vocal cords create faster vibrations which means that they vibrate with higher frequency than the vocal cords of the boys. Even when children grow up, we say the pitch of their voice is lowering since the frequency of the vibrations in the vocal cords become less.
By now it is understood that the correct option from the above is (b) frequency. Pitch is one of the factors that help us to distinguish between good sound and bad sound.

Note: There is not much difference between pitch and frequency. We understand the frequency of the sound with the help of pitch. We say the pitch is high if the frequency is high and vice-versa.
Amplitude tells about the loudness of the sound. It does not affect the frequency of the sound.
Wavelength is the distance between any two consecutive compressions or rarefactions of the wave.