In the Young’s double-slit experiment, the intensity of

In the Young’s double-slit experiment, the intensity of light at a point on the screen where the path difference is λ is K, (λ being the wave length of light used). The intensity at a point where the path difference is λ /4, will be:

For path difference λ, phase difference = 2π rad. For path difference λ/4, phase difference

=	π	rad.
	2

As K = 4I₀ so intensity at given point where path difference is

	λ
	4

K' = 4I₀ cos²		π			cos	π	= cos45°
		4				4

= 2I₀ =	K
	2