Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Wave Optics

Question:

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

Options:

$A\, μ\, r^{-2}$

$A\, μ\, r^{-1}$

$A\, μ\, r^{2}$

$A\, μ\, r^{1}$

Correct Answer:

$A\, μ\, r^{-1}$

Explanation:

For a point source, $I\, μ\,\frac{1}{r^2}$

and $A\, μ\,\sqrt{I}$   $A\, μ\,\sqrt{\frac{1}{r^2}}$  or $A\, μ\,\frac{1}{r}$