Question

A vibrating string fixed at both ends has consecutive harmonics at wavelengths of 4.0 m and 2.0 m. Then length of the string is –

• A. 1 m
• B. 2 m
• C. 4 m
• D. 8 m

Answer 1

Answer: (B)

2 m

Answer 2

l₁ = $\frac{2\mathcal{l}}{n}$

l₂ = $\frac{2\mathcal{l}}{n + 1}$

$\frac{4}{2}$ = $\frac{n + 1}{n}$

4n = 2n + 2

n = 1

4 = 2 × l

l = 2m