1)

 In Young's double slit experiment intensity at a point is (1/4) of the maximum intensity. Angular position of this point is (separation between slits is d)


A) sin1(λd)

B) sin1(λ2d)

C) sin1(λ3d)

D) sin1(λ4d)

Answer:

Option C

Explanation:

If a is the amplitude of the wave then

Imax4 = a2 = a2 +a2 +2aa cosΦ

or cos Φ = - 1/2 or Φ = 2π/3

Corresponding path difference,

Δx = ϕ×λ2π = (2π/3)×λ2π= λ/3

So, dsinθ=λ3

or θ = sin1(λ3d)