Question

Equation of wave traveling on string is given by
y = A sin (kx – wt). It is reflected at x = p/k.

Equation of reflected wave will be –

• A. A sin(kx + wt + p)
• B. A sin (kx + wt –2p)
• C. A sin(– kx – wt + p)
• D. A sin (kx + wt + 2p)

Answer 1

Answer: (B)

A sin (kx + wt –2p)

Answer 2

Let equation of reflected wave be

y = A sin(– kx – wt + f)

Phase difference between incident wave and reflected wave must be 'p' at x = p/k.

Ž – 2k$\left( \frac{\mathbf{\pi}}{\mathbf{k}} \right)$+ f = p

Ž f = 3p

\ Equation of reflected wave

= A sin (kx + wt – 2p)