Question

Frequency of a sonometer wire is n. Now its tension is increased 4 times and its length is doubled then new frequency will be
A. n/2
B. n
C. 2n
D. 4n

Answer 1

Correct Answer - B
`n_1 prop 1/l_1 sqrt(T_1) " and " n_2 prop (sqrtT_2)/(l_2)`
`n_2/n_1=dqrt(T_2/T_1) l_1/l_2 = sqrt4 xx 1/2 = 2/2 =1`
`therefore n_2=n_1 =n`