Question

Light from a coherent monochromatic light source with a wavelength of 5.20 ✕ 102 nm is incident on (and perpendicular to) a pair of slits separated by 0.310 mm. An interference pattern is formed on a screen 2.10 m from the slits. Find the distance (in mm) between the first and second dark fringes of the interference pattern.

Answer 1

y = 3.52 mm

Step-by-step explanation:

given,

wavelength of the light source (λ)= 520 nm

slits is separated (d) = 0.310 mm

distance to form interference pattern(D) = 2.10

distance between first and second dark fringe = ?

now, using displacement formula

`y = (m\lambda\ D)/(d)`

where y is the fringe width

for first and second dark fringe

now, m = 1

`y = (1* \lambda\ D)/(d)`

`y = (1* 520 * 10^(-6)\ 2100)/(0.310)`

y = 3.52 mm

width of the first bright fringe is equal to 3.52 mm

hence, distance between first and second dark fringe is equal to y = 3.52 mm