JEE Main2012PhysicsWaves and SoundActual
A wave represented by the equation y₁=a (k x- t) is superimposed with another wave to form a stationary wave such that the point x-0 is node. The equation for the other wave is
Options
- Aa (k x- t+ )
- Ba (k x+ t+ )
- Ca (k x+ t+ 2 )
- Da (k x- t+ 2 )
Correct answer
B. a (k x+ t+ )
Step-by-step solution
Since the point x=0 is a node and reflection is taking place from point x=0 . This means that reflection must be taking place from the fixed end and hence the reflected ray must suffer an additional phase change of or a path change of 2 . So, if y_ incident =a (k x- t) aligned y_ incident & =a (-k x- t+ ) & =-a ( t+k x) aligned Hence equation for the other wave y=a (k x+ t+ )