Question

Two narrow slits 84 mum apart are illuminated with light of wavelength 650 nm. What is the angle of the m = 3 bright fringe in radians What is the angle in degrees

Answer 1

The angle is 1.33°.

Step-by-step explanation:

Given that,

Distance
`d=84*10^(-6)\ m`

Wavelength = 650 nm

Number of fringe = 3

We need to calculate the angle

Using formula of angle for brightness

`d\sin\theta=m\lambda`

`\theta=\sin^(-1)(m\lambda)/(d)`

Where, d = distance

`\lambda` =wavelength

m = number of fringe

Put the value into the formula

`\theta=\sin^(-1)(3*650*10^(-9))/(84*10^(-6))`

`\theta=1.33^(\circ)`

Hence, The angle is 1.33°.