Question

If the amplitude of two light waves is $1$ and $2$ units respectively then the average intensity will be

• A. $3$ units
• B. $1$ units
• C. $5$ units
• D. $\sqrt{3}$ units

Answer 1

The correct option is C $5$ units

Intensity is proportional to the square of amplitude

So $I\propto A^2$

$I=A_1^2+A_2^2=1^2+2^2=5unit$