In a Young's double slit experiment two slits are separated by 2 mm and the screen is placed one meter away. When a light of wavelength 500 nm is used, the fringe separation will be:

Calculation:
The fringe separation in a Young's double slit experiment is given by the formula:

y = (λ × D) / d

Where:

• λ is the wavelength of light
• D is the distance between the slits and the screen
• d is the distance between the slits

Substitute the given values:

• λ = 500 nm = 500 × 10^-9 m
• D = 1 m
• d = 2 mm = 2 × 10^-3 m

The fringe separation (y) is:

y = (500 × 10^-9 × 1) / (2 × 10^-3) = 0.25 mm

The correct answer is: 0.25 mm