Question

Why does a convex lens of glass µ = 1.5 behave as a diverging lens when immersed in carbon disulphide of µ = 1.65?

Answer 1

The lens formula is given by

\(\frac{1}{f} = (\frac{\mu_2}{\mu_1} - 1) (\frac{1}{R_1} - \frac{1}{R_2})\)

here \(\frac{\mu_2}{\mu_1} = \frac{\mu_g}{\mu_c} = \frac{1.5}{1.65} <1\)

Hence f becomes -ve, so the lens behaves like a diverging lens.Hence f becomes -ve, so the lens behaves like a diverging lens.