Waves Ques 9

9. A standing wave having $3$ nodes and $2$ antinodes is formed between two atoms having a distance $1.21$ $\AA$ between them. The wavelength of the standing wave is

[1998]

(a) $1.21 $ $\AA$

(b) $2.42$ $ \AA$

(c) $6.05$ $ \AA$

(d) $3.63$ $ \AA$

Show Answer

Answer:

Correct Answer: 9.(a)

Solution:

  1. (a) Let $\ell$ be length of string

$ \ell=(\frac{\lambda}{2}) 2 \Rightarrow \lambda=\ell $

Hence, the wave length of standing wave

$\Rightarrow \lambda=\ell=1.21$ $ \AA$