Question

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 be the bubble appear ?

Answer 1

Correct Answer - `- 2.5 cm`
Here, `mu_(2) = 1.5, mu_(1) = 1, u = -3, v = ?`
`R = (- 10)/(2)cm = - 5cm`.
As refraction occurs from denser to rarer medium,
`:. -(mu_(2))/(u) + (mu_(1))/(v) = (mu_(2) - mu_(1))/(R )`
`- (3)/(2(-3)) + (1)/(v) = (1 - 3//2)/(-5) = (1)/(10)`
or `(1)/(v) = (1)/(10) - (1)/(2) = (- 4)/(10) v = - 2.5 cm`