Question

Two light waves of intensities 'I₁' and 'I₂' having same frequency pass through same medium at a time in same direction and interface. The sum of the minimum and maximum intensities is ______.

Options

• (I₁ + I₂)

• 2(I₁ + I₂)

• ${\displaystyle (\sqrt{{\text{I}}_1}+\sqrt{{\text{I}}_2})}$

• ${\displaystyle (\sqrt{{\text{I}}_1}-\sqrt{{\text{I}}_2})}$

Answer 1

Two light waves of intensities 'I₁' and 'I₂' having same frequency pass through same medium at a time in same direction and interface. The sum of the minimum and maximum intensities is 2(I₁ + I₂).

Explanation:

I_max = (a₁ + a₂)² and I_min = (a₁ - a₂)²

I_max + I_min = ${\displaystyle {\text{a}}_1^2+{\text{a}}_2^2+{\text{a}}_1^2+{\text{a}}_2^2}$

= 2${\displaystyle ({\text{a}}_1^2+{\text{a}}_2^2)}$

= 2(I₁ + I₂)