Question

In stationary waves, distance between a node and its nearest antinode is 20 cm. The phase difference between two particles having a separation of 60 cm will be

• A. Zero
• B. π/2
• C. π
• D. 3π/2

Answer 1

Answer: (D)

3π/2

Answer 2

$\frac{\lambda}{4} = 20 \Rightarrow \lambda = 80cm$, also $\Delta\varphi = \frac{\lambda}{2\pi}.\Delta x$

⇒ $\Delta\varphi =$ $\frac{60}{80} \times 2\pi = \frac{3\pi}{2}$