The question is incomplete! Complete question along with answer and step by step explanation is provided below.
Question:
A pair of narrow slits that are 1.8 mm apart is illuminated by a monochromatic coherent light source. A fringe pattern is observed on a screen 4.8 m from the slits. If there are 5.0 bright fringes/cm on the screen, what is the wavelength of the monochromatic light?
Given Information:
Distance from the double slits to the screen = D = 4.8 m
Double slit separation distance = d = 1.8 mm = 0.0018 m
Number of fringes = m = 5
Distance between fringes = y = 1 cm = 0.01 m
Required Information:
Wavelength of the monochromatic light = λ = ?
Answer:
Wavelength of the monochromatic light = λ = 7.5x10⁻⁷ m
Step-by-step explanation:
The wavelength of the monochromatic light can be found using young's double slits formula,
λ = yd/mD
where d is the double slit separation distance, D is the distance from the double slits to the screen, y is the distance between bright fringes and m is number of fringes.
λ = 0.01*0.0018/5*4.8
λ = 0.00000075 m
λ = 7.5x10⁻⁷ m
Therefore, the wavelength of the monochromatic light is 7.5x10⁻⁷ m