Q.

A guitar string of length 90 cm vibrates with a fundamental frequency of 120 Hz. The length of the string producing a fundamental frequency of 180 Hz will be ______ cm.     [2023]


Ans.

(60)

f=mv2l,  for fundamental mode n=1

f=v2l  f1l

f1f2l2l1

120180=l290  l2=60 cm