Question

In Young's double-slit experiment, the slit width and the distance of slits from the screen both are doubled. The fringe width

• A. increases
• B. decreases
• C. remains unchanged
• D. none of the above

Answer 1

The correct option is C

remains unchanged

Explanation:

Fringe width is the measure of distance between two adjacent bright/dark fringes. This is represented as $\beta =\frac{D\lambda }{d}$, where $D$ is the distance between the slit source and the screen, and $d$ is the slit separation. The width of the fringe will not vary as both $D$ and $d$ are enlarged to the same extent.

Hence, option C is the correct answer.