An air bubble in a glass sphere `(mu = 1.5)` is situated at a distance `3 cm` from a convex surface of diameter `10 cm`. At what distance from the surface will the bubble appear ?

Options

A. `2.5 cm`
B. `-2.5 cm`
C. `5 cm`
D. `-5 cm`

Answer

B

Explanation

Since refraction occurs from denser to rarer medium,
Therefore, ` - (mu_(2))/(u) + (mu_(1))/(v) = (mu_(1) - mu_(2))/(R)`
`- (3)/(2(-3)) + (1)/(v) = (1-3/2)/(-5) = 1/(10)` or `(1)/(v) = (1)/(10) - (1)/(2) = - (4)/(10)`
`rArr v = - 2.5 cm`