Q.

A sonometer wire of resonating length 90 cm has a fundamental frequency of 400 Hz when kept under some tension. The resonating length of the wire with a fundamental frequency of 600 Hz under the same tension is ____ cm.                  [2024]


Ans.

(60)

f0=400 Hz;  v=Tμ=constant

λ2=L;  v=f0λ

v2f0=Lv=2Lf0

L'=v2f'=2Lf02f'

=Lf0f'=90×400600=60