Q. An air bubble in a glass slab with refractive index 1.5 (near normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness (in cm) of the slab is
A) 8
B) 10
C) 12
D) 16
Explanation
[Solution] Real depths are 1.5 × 5 and 1.5 × 3; thickness = 7.5 + 4.5 = 12 cm. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.