Question

A fringe width of 6 mm was produced for two slits separated by 1 mm apart. The screen is placed 10 m away. The wavelength of light used is 'x' nm. The value of 'x' to the nearest integer is ______.

Options

• 600

• 500

• 700

• 300

Answer 1

A fringe width of 6 mm was produced for two slits separated by 1 mm apart. The screen is placed 10 m away. The wavelength of light used is 'x' nm. The value of 'x' to the nearest integer is 600.

Explanation:

Given,

Fringe width (β) = 6 mm = 6 × 10^-3 m

d = 1 mm = 1 × 10^-3 m

D = 10 m

Using the expression

β = `("D"lambda)/"d"`

6 × 10^-3 = `(lambdaxx10)/10^-3`

So, λ = 600 nm.