Question

To find the refractive index of a liquid by using a convex lens and a plane mirror observations

Answer 1

Answer:

Explanation: If theory f1 and f2 be the focal length of glass convex lens  and f be the focal length of their combination then ,

1/f = 1/f1 + 1/f2 or

1/f2 = 1/f - 1/f1

liquid lens formed is a plane concave lens with R1 = r ( radius of curvature of convex lens surface ), r2

From lens maker formula

1/f2 = (n-1) { 1/r1 - 1/r2}

so, n = 1+ r/f2

Source of error

1. liquid may not be quite transparent

2. The parallel may not be fully removed