Question

Light of wavelength 687 nm is incident on a single slit 0.75 mm wide. At what distance from the slit should a screen be placed if the second dark fringe in the diffraction pattern is to be 1.7 mm from the center of the diffraction pattern? A) 0.39 m

B) 0.47 m
C) 0.93 m
D) 1.1 m
E) 1.9 m

Answer 1

D = 0.93 m

Step-by-step explanation:

given,

wavelength of the light source (λ)= 687 nm

slits is separated (d) = 0.75 mm

distance to form interference pattern(D) =?

n = 2

now, using displacement formula

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

where y is the fringe width

y = 1.7 mm

`1.7 = (2* 687* 10^(-6)* D)/(0.75)`

`D = (1.7 * 0.75)/(2* 687* 10^(-6))`

D = 927.95 mm

D = 0.927 m

D = 0.93 m

Hence, the correct answer is option C