The interference fringes for sodium light of wavelength 5980angstrom in a double slit experiment have an angular width of 0 - Physics - Wave Optics

Question

The interference fringes for sodium light of wavelength
5980angstrom in a double slit experiment have an angular width of 0
20degree For what wavelength will this width be 10% greater

Gurpreet K. · Accepted Answer

Dear Student,

Angular width of fringes in an interference pattern is given by

θ=λd⇒θ∝λNew angular width θ'=θ+10100θ=1
1θ∴θ'θ=λ'λ⇒λ'=1
1×λ=1
1×5980 A˙⇒λ'=6578 A˙

The interference fringes for sodium light of wavelength 5980angstrom in a double slit experiment have an angular width of 0.20degree . For what wavelength will this width be 10% greater.