A stationary wave is formed having 4 nodes along the $120 \mathrm{~cm}$ length of the string. The wavelength…

A stationary wave is formed having 4 nodes along the $120 \mathrm{~cm}$ length of the string. The wavelength of the wave is
  1. $20 \mathrm{~cm}$
  2. $40 \mathrm{~cm}$
  3. $80 \mathrm{~cm}$
  4. $60 \mathrm{~cm}$

Solution

4 modes formed $\begin{aligned} \therefore 3 \lambda / 2 &=120 \mathrm{~cm} \\ \lambda &=\frac{240}{3} \mathrm{~cm} \end{aligned} \Rightarrow \lambda=80 \mathrm{~cm}$

Asked in: MHT CET 2020 (13 Oct Shift 2)

Practice more Waves and Sound questions on Aicharya