Question

A string has a mass of 100gm & is under a tension of 10N. What should be its length if the speed of transverse waves is to be 10m/s on the string.

(a) 1.8m

(b) 10m

(c) 1m

(d) 2m

The question was asked in an interview.

I would like to ask this question from Speed of a Travelling Wave topic in chapter Waves of Physics – Class 11

Answer 1

The correct answer is (c) 1m

To elaborate: v = √(T/μ),

μ = M/L.

V^2 = TL/M

Or L = v^2M/T

= 100 * 0.1/10

= 1m.