Question

In double slit experiment, the two slits are 1 mm apart and the screen is placed 1m away. A monochromatic light of wavelength 500 nm is used. What will be the width of each slit for obtaining 10 Maxima of double slit, within the central Maxima of Single Split pattern?

• A. 0.5 mm
• B. 0.02 mm
• C. 0.2 mm
• D. 0.1 mm

Answer 1

Answer: (C)

0.2 mm

Given,

Distance between two slits(d) is $1mm=1\times {10}^{-3}m$

Distance between screen and slit(D)=1m

The wavelength of Monochromatic light $\left(\lambda \right)=500nm=500\times {10}^{-9}m$

Let width of each slit is $x$

Now

Width of central maxima=width of 10th maxima

Therefore,

$\frac{2D\lambda }{x}=10\left(\frac{\lambda D}{d}\right)$

$\frac{2}{x}=\frac{10}{d}x=\frac{d}{5}=\frac{1}{5}\times {10}^{-3}m=0.2mm$

Correct option is C.