Q68 / 90 · JEE Main 2021 (27 Aug Shift 2) · Physics

The light waves from two coherent sources have same intensity $I_{1} = I_{2} = I_{0} .$ In interference pattern the intensity of light at minima is zero. What will be the intensity of light at maxima?

Solution

$I_{m i n i m u m} = 0$

${(\sqrt{I_{1}} - \sqrt{I_{2}})}^{2} = 0$

$\Rightarrow I_{1} = I_{2}$

$I_{\max} = {(\sqrt{I_{1}} + \sqrt{I_{2}})}^{2} = 4 I_{0}$

Hence, the correct answer is option: 'C'.