Question

If the width of slit $S$ in Young's double slit experiment is gradually increased.

• A. Bright fringes become brighter, dark fringes become darker.
• B. Bright fringes become less bright, dark fringes become less dark.
• C. Bright fringes become brighter, dark fringes become lighter.
• D. Bright fringes become less bright, dark fringes become darker

Answer 1

The correct option is C Bright fringes become brighter, dark fringes become lighter.

as the width increases the light enters coming from the slits increases hence intensity increases so "Bright fringes become brighter, dark fringes become lighter"
option $C$ is correct