Question

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

Answer 1

Lens formula=1/v+1/u=1/f

v=velocity

u=initial velocity

f=focal length

Answer 2

The refractive index of a liquid by using a convex lens and a plane mirror

Explanation:

If f₁ and f₂ be the focal length of convex lens and liquid lens and F is the focal length of their combination

then      $\frac{1}{F} = \frac{1}{f_{1} } +\frac{1}{f_{2} }$

From lens maker formula

$\frac{1}{f_{2} } = (n-1)[\frac{1}{R_{1} } -\frac{1}{R_{2} }]$

n = 1+$\frac{R}{f_{2} }$

putting values of f₂ ,n can be calculated