Question

What happens to the interference pattern if the two slits $s_{1}$ and $s_{2}$ in Young's double-slit experiment are illuminated by two independent identical sources?

• A. The intensity of the bright fringes is doubled
• B. The intensity of the bright fringes becomes four times
• C. Two sets of interference fringes overlap
• D. No interference pattern is observed

Answer 1

Answer: (D)

Independent light sources are incoherent. Hence a permanent interference pattern is not obtained.