Read the information given below.

It is useful to design lenses of derived focal length using surface of suitable radii of curvature. Lens maker formula helps in finding various unknowns and is widely applied.

If a convex lens made of a material of refractive index $n_2$ is immersed in a liquid of refractive index $n_1$ such that $n_1 = n_2$, the incident beam of light will emerge as shown

The correct answer is option (4) :

From lens marker's formula

$\frac{1}{f}=\left(\frac{\mu_f}{\mu_g}-1\right)\left(\frac{1}{R_1}-\frac{1}{R_2}\right)$

If $\mu_f= \mu_g$, then $\frac{1}{f}=0$

$⇒f=∞$

Hence ray diagram will be