A stationary wave is represented by $\mathrm{y}=10 \sin \frac{\pi \mathrm{x}}{4} \cos 20 \pi \mathrm{t}$…

A stationary wave is represented by $\mathrm{y}=10 \sin \frac{\pi \mathrm{x}}{4} \cos 20 \pi \mathrm{t}$ where ' $\mathrm{x}$ ' and ' $\mathrm{y}$ ' are expressed in $\mathrm{cm}$ and $^{\prime} t^{\prime}$ in second. Distance between two consecutive nodes is
  1. $4 \mathrm{~cm}$
  2. $1 \mathrm{~cm}$
  3. $8 \mathrm{~cm}$
  4. $2 \mathrm{~cm}$

Solution

The stationary wave is: $y=10 \sin \left(\frac{\pi x}{4}\right) \cos (20 \pi t)$ Nodes occur where $\sin \left(\frac{\pi x}{4}\right)=0$ : $\frac{\pi x}{4}=n \pi \quad \Rightarrow \quad x=4 n \mathrm{~cm}$ Distance between consecutive nodes: $\Delta x=4 \mathrm{~cm}$

Asked in: MHT CET 2020 (12 Oct Shift 2)

Practice more Waves and Sound questions on Aicharya