Q. The intensity ratio of two waves is 1:9. The ratio of their amplitudes, is
A) 3:1
B) 1:3
C) 1:9
D) 9:1
Explanation
(b) Intensity $\propto (amplitude)^{2}$
$\therefore\ \frac{I_{1}}{I_{2}} = \frac{a_{1}^{2}}{a_{2}^{2}}$
$\frac{1}{9} = \frac{a_{1}^{2}}{a_{2}^{2}}$
$\Longrightarrow \frac{a^{1}}{a^{2}} = \frac{1}{3}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.