Question

In interference with coherent sources, the fringe width varies as:

• A. Directly as wavelength
• B. Inversely as wavelength
• C. Directly as the separation between slits
• D. Inversely as the distance between the slits and screen

Hint:

In Young’s Double Slit Experiment, increasing the wavelength increases the fringe width.

Answer 1

The Correct Option is A

For Young’s Double Slit Experiment, the fringe width \( \beta \) is given by:
\[ \beta = \frac{\lambda D}{d} \] where:
- \( \lambda \) = wavelength of light
- \( D \) = distance between slits and screen
- \( d \) = separation between slits
Since \( \beta \propto \lambda \), the fringe width increases with wavelength.