Question

If prism angle a = 1⁰, m = 1.54, distance between prism and source a = 0.3m, l = 180p nm then in Fresnal biprism find the value of b (fringe width)-

• A. 10^–4 m
• B. 10^–3 mm
• C. 10^–4 × p m
• D. p × 10^–3 m

Answer 1

Answer: (A)

10^–4 m

Answer 2

By using b= $\frac{(a + b)\lambda}{2a(\mu - 1)\alpha}$ after putting all values get b = 10^–4 m.