Question

Light waves from two coherent sources arrive at two points on a screen with a path difference of zero and λ/2. The ratio of the intensities at the points is ______ 

विकल्प

• one : two

• one : one

• two : one

• infinity : one

Answer 1

Light waves from two coherent sources arrive at two points on a screen with a path difference of zero and λ/2. The ratio of the intensities at the points is infinity : one.

Explanation:

When path difference is zero, the resultant intensity I = 4I₀, where I₀ is the intensity of the individual waves.

When the path difference is `lambda/2`, the intensity I' = 0

∴ `I/I^'= (4I_o)/0 = ∞`