Question

In young's double slit experiment fringe order is represented by m then fringe width is

• A. independent of m.
• B. directly proportional to m.
• C. directly proportional to (2m+1).
• D. inversely proportional to (2m+1).

Answer 1

Answer: (A)

independent of m.

The distance of a fringe from the center of the screen will depend on its order but the fringe width is the gap between two consecutive bright or dark fringes. It is constant in the experiment and does not depend on fringe order.

Fringe width $=\frac{(m+1)\lambda L}{d}-\frac{m\lambda L}{d}=\frac{\lambda L}{d}$