Question

The second-order bright fringe in a single-slit diffraction pattern is 1.35 mm from the center of the central maximum. The screen is 75 cm from a slit of width 0.838 mm. Assuming monochromatic incident light, calculate the wavelength. Answer in units of nm.

Answer 1

Answer:

The wavelength is 754.2 nm.

Explanation:

Given that,

Diffraction pattern y= 1.35 mm

Width = 0.838 mm

Distance D= 75 cm

We need to calculate the wavelength

Using formula of diffraction pattern

$y=\dfrac{m\lambda D}{d}$

$\lambda=\dfrac{yd}{mD}$

Where, y = diffraction pattern

m = order

d = width

D = distance

Put the value into the formula

$\lambda=\dfrac{1.35\times10^{-3}\times0.838\times10^{-3}}{2\times75\times10^{-2}}$

$\lambda=7.542\times10^{-7}\ m$

$\lambda=754.2\ nm$

Hence, The wavelength is 754.2 nm.