Answer:
a ) 1.267 radian
b ) 1.084 10⁻³ mm
Explanation:
Distance of screen D = 1.65 m
Width of slit d = ?
Wave length of light λ = 687 nm.
Distance of second minimum fro centre y = 2.09 cm
Angle of diffraction = y / D
= 2.09 /1.65
= 1.267. radian
Angle of diffraction of second minimum
= 2 λ / d
so 2 λ / d = 1.267
d = 2 λ / 1.267 = (2 x 687 ) /1.267 nm
=1084.45 nm = 1.084 x 10⁻³ mm.
