Question

A double slit experiment is immersed in water of refractive index 1.33. The slit separation is 1 mm, distance between slit and screen is 1.33 m. The slits are illuminated by a light of wavelength 6300 Å. The fringe width is ______.

Options

• 6.9 × 10^-4m

• 6.3 × 10^-4m

• 5.8 × 10^-4m

• 8.6 × 10^-4m

Answer 1

A double slit experiment is immersed in water of refractive index 1.33. The slit separation is 1 mm, distance between slit and screen is 1.33 m. The slits are illuminated by a light of wavelength 6300 Å. The fringe width is 6.3 × 10^-4m.

Explanation:

fringe width = X `=(lambda_WD)/d`

`lambda_W=(6.3xx10^-7)/1.33,` D = 1 m, d = 10^-3 m   [on substituting and solving]

X = 6.3 × 10^-4 m