Physics Circle home Student Login

Home›Chapters›Wave Optics PYQs›Superposition, Coherence & Intensity›Question 11

MHT CET 2026 (19 Apr, Shift 1) · Superposition, Coherence & Intensity

Superposition, Coherence & Intensity question from MHT CET 2026 (19 Apr, Shift 1)

Q11MHT CET 2026 · 19 APR · SHIFT 1Medium

Superposition, Coherence & Intensity

In Young's double slit experiment, the wavelength of light used is λ\lambda. The intensity on the screen at a point for path difference 'λ\lambda' is 'X'. The intensity at the point for path difference (λ6)\left(\frac{\lambda}{6}\right) is (cos⁡180∘=−1, cos⁡30∘=32\cos 180^\circ = -1,\ \cos 30^\circ = \frac{\sqrt{3}}{2})

Show answer and solution

Answer: (c)

  1. Path difference λ\lambda gives ϕ=2π\phi = 2\pi, a bright fringe, so X=ImaxX = I_{max}.
  2. For λ/6\lambda/6: ϕ=π/3\phi = \pi/3, I=Xcos⁡230∘=3X4I = X\cos^2 30^\circ = \dfrac{3X}{4}.
  3. So the answer is (c) 3X4\dfrac{3X}{4}.
Report a mistake

More questions on Superposition, Coherence & Intensity