Interference was observed in interference chamber when air was present, now the chamber is evacuated and if the same light is used, a careful observer will see

Options

A. interference in which width of the fringe will be slightly increased
B. Interference with bright bond
C. Interference with dark bond
D. All of the above

Answer

A

Explanation

The refreactive iondex of air is slightly more than 1.
When chamber is evacuated, refractive index decreases and hence the wavelength increases and fringe width also increases.