Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Wave Optics

Question:

If A is the amplitude of the wave coming from a line source at a distance r, then

Options:

$A \propto  r$

$A \propto  r^{-1/2}$

$A\propto r^{-2}$

$A \propto  r^{1/2}$

Correct Answer:

$A \propto  r^{-1/2}$

Explanation:

For a line source, $I \propto \frac{1}{r}$

and $A \propto \sqrt{I}$    $A \propto  r^{-1/2}$