Question

For the stationary wave y = 4 sin $\left(\frac{\pi x}{15}\right)cos\left(96\pi t\right)$ , the distance between

anodeand the next antinode is

[MP PMT 1987]

• A. 7.5
• B. 15
• C. 22.5
• D. 30

Answer 1

The correct option is A

7.5

Comparing given equation with standard equation

y = 2 a sin $\frac{2\pi x}{\lambda }cos\frac{2\pi vt}{\lambda }givesus\frac{2\pi }{\lambda }=\frac{\pi }{15}\Rightarrow \lambda =30$

Distance between nearest node and antinodes

= $\frac{\lambda }{4}=\frac{30}{4}=7.5$