Question

Light from a helium-neon laser (λ = 633 nm) illuminates two slits spaced 0.50 mm apart. A viewing screen is 2.5 m behind the slits. What is the spacing between two adjacent bright fringes?

Answer 1

Answer:

Explanation:

Given

wavelength $\lambda =633\ nm$

distance between two slits $d=0.5\ mm$

Screen is placed at a distance $L=2.5\ m$

Location of a (n+1)th bright fringe is given by

$x_{n+1}=\frac{L}{2d}(n+1)\lambda$

for nth bright fringe

$x_n=\frac{L}{2d}(n)\lambda$

Distance between two bright fringes

$x_{n+1}-x_n=\frac{L}{2d}\cdot \lambda$

$x_{n+1}-x_n=\frac{2.5}{2\times 0.5\times 10^{-3}}\cdot 633\times 10^{-3}$

$x_{n+1}-x_n=1.582\ mm$