Question

Consider the situation shown in the figure. The two slits S1 and S2 placed symmetrically around the central line are illuminated by a monochromatic light of wavelength λ. The separation between the slits is d. The light transmitted by the slits falls on a screen ∑1 placed at a distance D from the slits. The slit S3 is at the central line and the slit S4 is at a distance z from S3. Another screen ∑2 is placed a further distance D away from ∑1. Find the ratio of the maximum to minimum intensity observed on ∑2 if z is equal to

Answer 1

i) when x= λD/2d

at S4 minimum intensity occurs .(dark fringes )

Amplitude = A= 0

aT S3 PATH DIFFERENCE = 0

Maximum intesity occurs

Amplitude=2r

so on ∑2 screen, I max/ I min=(2r+0)²/(2r-0)²=1

II)

when z=  λD/d  At S4  maximum Intensity occurs

Amplitude = √2r

At s3 , also maximum intensity occurs

Amplitude=2r

∴I max/Imin =(2r+2r)²/(2r-2r)²= ∞

III) When  x=  λD/4d

at s4 Intensity = Imax/2

Amplitude = √2r

At s3  Intensity is maximum

Amplitude =2r

Imax/ Imin =(2r+√2r)²/(2r-√2r)²=34

Answer 2

Explanation:

hope it helps you..............