Question

In a double slit experiment, it is observed that the angular width of one fringe formed on the screen is 0.2°. The wavelength of light used in the experiment is 500 nm. Calculate the separation of the two slits.

Answer 1

Given: Angular fringe width (θ) = 0.2° = `0.2 xx pi/180`rad

Wavelength (λ) = 500 nm = 500 × 10⁻⁹ m

So, the separation of slits,

d = `lambda/theta`

= `(500 xx 10^-9 xx 180)/(0.2 xx 3.14)`

= 0.143 mm