Question Detail
Question
Light of wavelength 575 nm falls on a double-slit and the third order bright fringe is seen at an angle of 6.5°. What is the separation between the double slits?
Correct Answer
Option C is the correct answer.
Detailed Explanation
d sin θ = mλ. d = mλ / sin θ = (3 × 575e-9) / sin 6.5° = 1.725e-6 / 0.1132 = 1.524e-5 m = 15.24 μm ≈ 15 μm.
Hint
Use d sin θ = mλ.