question_answer

A concave mirror has radius of curvature of 40 cm. It is at the bottom of a glass that has water filled up to 5 cm (see figure). If a small particle is floating on the surface of water, its image as seen, from directly above the glass, is at a distance d from the surface of water. The value of d is close to : (Refractive index of water = 1.33)

[JEE Main Held on 12-4-2019 Morning]

A) 8.8 cm

B) 11.7 cm

C) 6.7 cm

D) 13.4 cm

Correct Answer: A

Solution :

[a] Light incident from particle P will be reflected at mirror

This image will act as object for light getting refracted at water surface

So, object distancebelow water surface.

After refraction, final image is at