Q162 / 225 · JEE Main 2002 · Physics
A wave $y=a \sin (\omega t-k x)$ on a string meets with another wave producing a node at $x=0$. Then the equation of the unknown wave is
- A$y=a \sin (\omega t+k x)$
- Correct answerB$y=-a \sin (\omega t+k x)$
- C$\mathrm{y}=\mathrm{a} \sin (\omega \mathrm{t}-\mathrm{kx})$
- D$\mathrm{y}=-\mathrm{a} \sin (\omega \mathrm{t}-\mathrm{kx})$
Solution
$y_1+y_2=a \sin (\omega t-k x)-a \sin (\omega t+k x)$
$=-2 a \cos \omega t \times \sin k x \Rightarrow y_1+y_2=0$ at $x=0$
Hence, the correct answer is option: 'B'.