Question 24: Waves Optics

Question

Two coherent waves of intensities $I_1$ and $I_2$ pass through a region at the same time in the same direction. The sum of maximum to minimum intensities is

Accepted Answer

When two coherent waves of intensities $I_1$ and $I_2$ interfere, their extreme intensities are
Ã¢ÂÂ¢ Constructive (maximum):
$$I_{\max} = I_1 + I_2 + 2\sqrt{I_1\,I_2}$$
Ã¢ÂÂ¢ Destructive (minimum):
$$I_{\min} = I_1 + I_2 - 2\sqrt{I_1\,I_2}$$
Adding these gives
$$I_{\max} + I_{\min} = \bigl(I_1 + I_2 + 2\sqrt{I_1I_2}\bigr) + \bigl(I_1 + I_2 - 2\sqrt{I_1I_2}\bigr) = 2\,(I_1 + I_2)\,. $$
So the correct choice is
Option B: $\;2\,(I_1 + I_2)$.

Answer

$\left(I_1+I_2\right)$

Answer

$2\left(I_1+I_2\right)$

Answer

$2\left(\sqrt{I_1}+\sqrt{I_2}\right)^2$

Answer

$\left(I_1+I_2\right)^2$

Waves Optics

Two coherent waves of intensities I_1 and I_2 pass through a region at the same time in the same direction. The sum of maximum to minimum intensities is

Choose the correct answer: