Question

Light of wavelength 6000 Å incident on a single slit. The first minimum of the diffraction pattern is obtained at 4 min from the centre. The screen is at a distance of 2m from the silt. The slit width will be ______.

Options

• 0.3 mm

• 0.2 mm

• 0.15 mm

• 0.1 mm

Answer 1

Light of wavelength 6000 Å incident on a single slit. The first minimum of the diffraction pattern is obtained at 4 min from the centre. The screen is at a distance of 2m from the silt. The slit width will be 0.3 mm.

Explanation:

From, a sinθ = nλ,

a`x/"D"` = nλ or a = `("n"lambda"D")/x`

= `(1xx6000xx10^-10xx2)/(4xx10^-3)`

∴ A = 3 × 10^-4

= 0.3 mm