Question

In the Fresnel circular aperture setup, the distances from the aperture to the light source and the reception screen are 1.5 m and 0.6 m, respectively. The wavelength is 630 nm. Suppose that the radius of the aperture can be increased from 0.5 mm, determine: (a) The first two radii when the center intensity at the reception screen is maximum. (b) The first two radii when the center intensity is minimum.

Answer 1

Explanation:

The width of the central maximum is given by

W = 2 λ L / a

where W is the width of the central maximum

λ is the wavelength of the light used.

L is the distance between the aperture and screen

a is the width of the slit or aperture

So we can see that if any one quantity is varied by keeping others constant in the above formula , there would be a change in width of central maximum.