Question

Visible light of wavelength 6000 × 10^{– 8} cm falls normally on a single slit and produces a diffraction pattern. It is found that the second diffraction minimum is at 60° from the central maximum. If the first minimum is produced at θ₁, then θ₁ is close to :

(1) 20°  

(2) 45°

(3) 30°

(4) 25°

Answer 1

Answer is (4) 25°

For 2^nd minima

So for 1^st minima is

Answer 2

Answer is (4) 25°