Optical Fibres

Q. What would be the refractive index of the core of an optical fiber if the critical angle is ${60}^{\circ }$ and the refractive index of the cladding is $\sqrt{3}$ ? (Cladding is the outer covering in the optical fiber.) Refer the figure given below:-

1. $\sqrt{2}$
2. $2$
3. $3$
4. $2.5$

Q.

In an optical fibre, the refractive index of the core should be lesser than the refractive index of the cladding.

1. True

2. False