Question

Example 1. A plane wave front of wave length 5000Ả is incident
perpendicularly on a circular aperture. The dark rings of 5 mm radius is observed
around the central maximum on screen. The distance between the screen and
aperture is 2 m. Find the diameter of a circular aperture.
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Answer 1

Answer:

Example 1. A plane wave front of wave length 5000Ả is incident

perpendicularly on a circular aperture. The dark rings of 5 mm radius is observed

around the central maximum on screen. The distance between the screen and

aperture is 2 m. Find the diameter of a circular aperture.

Answer 2

Answer:

a=2.44*10^-4 m

Explanation:

Given

x=5mm

wavelength (√=5000 Å)

and f=2m

we know that

x=1.22f√/a

a=1.22f√/x

a=1.22 * 2 * 5*10^-7 / 5*10^-3

Hence value of a is

a=2.44*10^-4m