Electric lines of force Why cant electric lines of force pass through the charged sphere? Well, basically that's how a Faraday cage works, but how can it be so?
 A: If you mean non-conducting sphere, It can not be like Faraday cage because if you put for example a point charge out of the sphere you will have non-zero electric field inside because the sphere is not able to rearrange charges on it to cancel the effect of external sources 
A: An electric field line follows the direction of change of an electrostatic potential. If you choose a point where the field line start, the line will go where the electrostatic potential changes most. This is equal to the force which is exerted on a charged particle which resides at a particular point.
Example: Assume a system of two infinitely large capacitor plates. If you start your field line (you can really choose where you want to start it!) in the middle between the two capacitors, it will take the shortest possible route to one of the capacitor plates.
Back to your question/comment: If you have a conducting sphere, the potential in it is constant. Because a field line follows the direction of change, you can't have field lines there.
Mathematically, a field line $\mathbf r(t)$ for an electrostatic potential $\Phi(\mathbf r)$ is defined as
$$\frac{d\mathbf r(t)}{dt}\propto \nabla \Phi(\mathbf r(t))$$
That's not so important, but I note it for the sake of completeness.
