Question

A 0.6 m long stretched wire is made to vibrate in two different modes as shown in figure

(a) 

(b)

(i) If the frequency of the note produced in (b) is n, what is the frequency in case (a)?
(ii) In which case (a) or (b), is the note louder? Give reasons.
(iii) In which case is the pitch higher? Give reason.

Answer 1

(i) The frequency of the note represented by (n) is 2 times represented by (a). Since the frequency of the note in (b) is n, hence the frequency of a note in (i) is 1/2 or n/2.
(ii) The note in (a) is louder, the reason being its amplitude is greater than the amplitude of note represented in (b), as the loudness being directly proportional to amplitude.
(iii) Pitch is directly proportional to the frequency of the sound notes. The frequency of a note in figure (b) is more (double) than the frequency of a note in (a). So the pitch of the note (b) is higher than that of note (a).