Question

Light from a point source in air falls on a convex curved surface of radius 20 cm and refractive index 1.5. If the source is located at 100 cm from the convex surface, the image will be formed at____ cm from the object.

Answer 1

Correct answer is : 200

\(\frac {\mu _2}{v}-\frac {\mu _1}{u}=\frac {\mu _2 -\mu _1}{R}\)

\(\frac {1.5}{v}-\frac {1}{-100}=\frac {1.5-1}{20}\)

v = 100 cm

Distance from object 

= 100 + 100 

= 200 cm