Q. In a Fresnel biprism experiment, the two positions of lens give separation between the slits as 16 cm and 9 cm, respectively. What is the actual distance of separation?
A) 12.5 cm
B) 12 cm
C) 13 cm
D) 14 cm
Explanation
(b) In Fresnel biprism, the virtual images act as two coherent sources and from these two virtual images rays superimposed and interference fringes are formed in overlapping region AB on a screen placed at O.
In order to measure the distance $2d$ between the virtual sources $S_{1}$ and $S_{2}.$ Glaze brook gave a method, known as magnification method due to Glaze brook. If $d_{1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.