MCQ
Figure, shows a stationary wave between two fixed points $P$ and $Q$. Which point$(s)$ of $1, 2$ and $3$ are in phase with the point $X?$
- A$1, 2$ and $3$
- B$1$ and $2$ only
- C$2$ and $3$ only
- ✓$3$ only
✓
Answer
Correct option: D.
$3$ only
d
Two points on a transverse wave having same magnitude of displacement from the equilibrium line are said to be in the same phase only if the direction of displacement and direction of motion are also same. For point $1,$ the direction of displacement is opposite (it can be clearly seen if $\mathrm{X}$ is on the upper side of equilibrium, point $1$ will be on lower side and $vice-versa$). Also, point $2$ has an opposite direction of motion. So only point $3$ is in phase with $x$.
Two points on a transverse wave having same magnitude of displacement from the equilibrium line are said to be in the same phase only if the direction of displacement and direction of motion are also same. For point $1,$ the direction of displacement is opposite (it can be clearly seen if $\mathrm{X}$ is on the upper side of equilibrium, point $1$ will be on lower side and $vice-versa$). Also, point $2$ has an opposite direction of motion. So only point $3$ is in phase with $x$.
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