Question

In an interference pattern by two identical slits, the
intensity of central maxima is I. What will be the
intensity of the same spot, if one of the slits is
closed?
E
-10
a
-17 -
(4) 21​

Answer 1

The intensity at same spot, if one of the slits is closed is I/4

Explanation:

Let the intensity from one slit be I₁

Let the intensity from another slit be I₂

From question, the intensity of the same spot is need to be found.

⇒ I₁ = I₂ = a²

Now, the maximum intensity is given by the formula:

Imax = (a + a)² = (2a)² = 4a² = I

From question, we need to find intensity when slits is closed.

I₁ = a² = I/4