The tension in a piano wire is 10 N. What should be the tension in the wire to produces a note of double the frequency ?

Options

A. 5 N
B. 20 N
C. 40 N
D. 80 N

Answer

C

Explanation

We know that in a stretched string
`v = (1)/(2l) sqrt((T)/(m)) rArr " " v prop sqrt(T)`
`therefore (v_(2))/(v_(1)) = sqrt((T_(2))/(T_(1)))`
`rArr " " (2v)/(V) = sqrt((T_(2))/(10)) rArr T_(2) = 40 N `
Correct choice is (c).