how can electric field exist inside a uniform charge solid... when by gauss law electric field is zero inside a conductor
Not all solids are conductors. A "uniformly charged" solid has a constant charge density throughout the volume, and is not a conductor.
Good question! When we talk about the electric field inside a uniform charge solid, we need to consider the difference between conductors and insulators.
Gauss's law states that the electric field inside a conductor is zero when it is in electrostatic equilibrium. This is because within a conductor, charges are free to move, and in equilibrium, they redistribute themselves in such a way that cancels out any internal electric fields. Essentially, the electric charges redistribute so that they create an electric field that counteracts any external electric field.
However, when we talk about a uniform charge solid that is an insulator (non-conductor), the situation is different. Insulators do not have free charges that can move easily. So, unlike conductors, they cannot redistribute their charges to cancel out an internal electric field.
In the case of a uniformly charged insulator, the electric field does exist inside the solid. The charges are fixed in position and create an electric field that extends into the material. This electric field is a result of the presence of the charges within the solid and their electrostatic interaction with each other.
To calculate or determine the electric field inside a uniform charge solid, you would typically use Coulomb's law, which describes the force between two charged particles. You can find the electric field at a given point by summing up the contributions from all the charges in the solid, taking into account their distances and the direction of the field vectors.
So, in summary, while the electric field inside a conductor in equilibrium is always zero, the electric field inside a uniform charge solid (insulator) can exist and is determined by the fixed charges within the solid.