Question

If a standing wave is vibrating in the fourth harmonic and the wavelength is λ, what is the length of the string.

(a) 2λ

(b) λ

(c) 4λ

(d) λ/4

Answer 1

Correct choice is (a) 2λ

For explanation I would say: If the length of string is L, then the wavelength of the standing wave is 2L/n.

Or we can say L = nλ/2, where n corresponds to nth harmonic.

∴ L = 4λ/2

= 2λ.