Question

The sketches I to IV in figure show sound waves, all formed in the same time interval. Which diagram shows note from a musical instrument ?

• A. III
• B. II
• C. IV
• D. I

Answer 1

The correct option is C IV

The sounds from instruments are never pure notes, i.e. of one frequency, the only exception being a tuning fork. Rather they consist of one main note which is predominant and other smaller notes called overtones. The main note or fundamental note is also referred to as the first harmonic and if it has a frequency f, the overtone with frequency 2f is called the second harmonic and the overtone with frequency 3f is called the third harmonic and so on. The sum of all the harmonics is the waveform and determines the quality of the sound.
Hence, the figure IV is a note from the musical instrument.