JEE Main 2026 Physics question
In interference experiment the path difference between two interfering waves at a point A on the screen is λ/3, where λ is the wavelength of these waves, and at another point B the path difference is λ/6. The ratio of intensities at points A and B is .
Answer: (C)
Solution
I∝cos²(φ/2) with φ=2πΔ/λ. At A: φ=2π/3, cos²(π/3)=1/4. At B: φ=π/3, cos²(π/6)=3/4. Ratio /=1/3.