Answer:(a)9.685 mm
(b)4.184 mm
Explanation:
Given
Wavelength of light [tex](\lambda )=565nm \approx 565\times 10^{-9}m[/tex]
Width of slit(b)=0.210
(a)Width of central maximum located 1.80m from slit
[tex]=\frac{2\lambda L}{b}[/tex]
[tex]=\frac{2\times 565\times 10^{-9}\times 1.8}{0.210\times 10^{-3}}[/tex]
=9.685 mm
(b)Width of the first order bright fringe
[tex]Y_1=\frac{\lambda \times L}{b}[/tex]
[tex]Y_1=\frac{565\times 10^{-9}\times 1.8}{0.210\times 10^{-3}}[/tex]
[tex]Y_1=4.84mm[/tex]