Question

The contrast in the bright and dark fringes in any interference pattern depends on

• A. Fringe width.
• B. Wavelength.
• C. Intensity ratio of the sources.
• D. Distance between the sources.

Answer 1

The correct option is C Intensity ratio of the sources.

Contrast indicates the ratio of maximum possible intensity on screen to the minimum possible intensity.

As
$\frac{I_{max}}{I_{min}}=\frac{(\sqrt{I_1}+\sqrt{I_2}{)}^2}{(\sqrt{I_1}-\sqrt{I_2}{)}^2}$

So it depends on the intensity of the two sources.

Hence, $\left(C\right)$ is the correct answer.