Question

The first minimum of a single slit diffraction pattern is observed at angle 2° with a light of wavelength 510 nm. The width of this slit is ____________.

Options

• 1.5 x 10^-5 m

• 0.1 mm

• 1.5 mm

• 0.015 mm

Answer 1

The first minimum of a single slit diffraction pattern is observed at angle 2° with a light of wavelength 510 nm. The width of this slit is 1.5 x 10^-5 m.

Explanation:

In single slit diffraction, for small angle,

`"d" theta = 2"n" lambda/2  "is the condition for minimum"`

`therefore "d" = ("n"lambda)/theta`

`= (1 xx 510 xx 10^-9)/(2° xx pi/180)^"e"`

`therefore "d" = 1.5 xx 10^-5  "m"`