Question

light of wavelength 5800 A^0 is incident normally on a slit of width 0.20 mm. diffraction pattern is observed on screen 2m away from slit from central bright fringe the distance of first dark fringe on either side? ​

Answer 1

Answer:

580mm

Explanation:

n lambda =d sin theta

n=0 central bright fringe

n=1 first bright fringe

wavelength=5800 A=5800×10^-10m

1m=10^-3mm

=5800×10^-7mm

d=0.2mm

D=2m

a=0.20mm

=0.20×10^-4cm

Wavelength=5.8×10^-7cm

a sin theta=n× wavelengths

for the 1st dark fringe

a sin theta= Lambda / a

=x/D

x= lambda× D / a

x=5.8mm