Optics Question 810
Question: A glass sphere, refractive index 1.5 and radius 10 cm, has a spherical cavity of radius 5 cm concentric with it. A narrow beam of parallel light is directed into the sphere. Find the final image and its nature.
Options:
A) 25 cm left of
B) 25 cm right of
C) 15 cm left of
D) 20 cm right of
Show Answer
Answer:
Correct Answer: A
Solution:
[a] We will have single surface refractions successively at the four surfaces
Do not forget to shift origin to the vertex of respective surface.
First image is object for the refraction at second surface.
For refraction at surface
For refraction at surface
For refraction at surface
The final image is virtual, formal at 25 cm to the left of the vertex of surface
