Question

When we here a sound, we can identify its source from:
(A) amplitude of sound
(B) intensity of sound
(C) wavelength of sound
(D) overtones present in the sound

Answer 1

Fundamental frequency of sound refers to the overall frequency with which the sound travels in a medium. Along with the fundamental frequency of sound, there are other frequencies too travelling along with the sound, which facilitates the sensation of sound through human ears from its source. The series of all components of a sound wave is called a harmonic series.

Complete answer:
We know that sound travels in the form of waves. Also do we know that wavelength, frequency and intensity are some of the important characteristics of a sound wave. Among these, fundamental frequency of sound is defined as the overall frequency with which the entire sound wave propagates in a medium. Now, when a sound propagates through a medium, there are other frequencies too, which travel along with the fundamental frequency of sound. Values of these frequencies are generally above the fundamental frequency of sound. The sinusoidal components present in these frequencies above the fundamental frequency of sound are called overtones present in the sound. All the components of a sound wave, including the components of fundamental frequency as well as the overtones present in the sound are termed as partials. Another name given to the series of partials is harmonic series. It is these overtones present in the harmonic series of sound that helps us to identify the source of sound.
Overtones are categorized into two as follows. The overtones which are perfect integer multiples of the fundamental frequency of sound are called harmonic overtones whereas the overtones that are not anywhere near the fundamental frequency of sound are called as inharmonic overtones.

Hence, from the above explanation, we can say that option (D) is the correct answer.

Note:
According to musical language, fundamental frequency of sound is called a fundamental tone. It is also called the first harmonic. At the same time, the frequency just above the fundamental frequency is called a second overtone or second harmonic. Similarly, in an increasing order of their positions, the frequencies above the fundamental frequency are termed as third overtone/harmonic, fourth overtone/harmonic, fifth overtone/harmonic, etc.