Question

Light of wavelength 500 nm is used to form interference pattern in young's double slit experiment. A uniform glass plate of refractive index 1.5 and thickness 0.1 mm is introduced in path of the one of the interfering beams. The number of fringes which will shift is-

• A. 100
• B. 200
• C. 300
• D. 400

Answer 1

Answer: (A)

100

Answer 2

(m _ 1)t $\frac{D}{d} = \frac{nD}{d}\lambda$, (m _ 1)t = nl

\ (1.5 _ 1) × 0.1 × 10^–3 = n × 500 × 10^–9

\ n = 100