Q.

A string of length 1 m and mass 2×10-5 kg is under tension T. When the string vibrates, two successive harmonics are found to occur at frequencies 750 Hz and 1000 Hz. The value of tension T is ________ Newton.         [2023]


Ans.

(5)

As two successive harmonics are found to occur at frequency 750 Hz and 1000 Hz

f=P2Tμ

So, 750=P2Tμ                   ...(i)

and,  1000=P+12Tμ               ...(ii)

Dividing eq. (ii) by (i),

43=P+1P

  P=3

Putting this value of P=3 in eq. (ii) and solving we get tension T,

1000=42T2×10-5

  T=5 N