Question

If the source of light used in a Young's double slit experiment is changed from red to violet.

• A. The fringes will become brighter
• B. Consecutive fringes will comes closer
• C. The intensity of minima will increase
• D. The central fringe-will became a dark fringe

Answer 1

The correct option is B Consecutive fringes will comes closer

Fringe width, $\beta =\frac{\lambda D}{d}$

The wavelength of red light is greater than the wavelength of violet light, so fringe width will reduce. And the consecutive fringes will come closer.