Explain the electrostatics of conductors. Explain the effects produced inside a metallic conductor placed in an external electric field.

(N/A) In metallic conductors, the charge carriers are electrons. In a metal, the outer (valence) electrons part away from their atoms and are free to move.
These electrons are free from their parent atoms but are not free to leave the metal. Hence, these free electrons form a kind of 'gas'.
Free electrons collide with each other and with the ions, moving randomly in different directions.
When placed in an external electric field $\vec{E}$, they drift against the direction of the field and get deposited on one surface, while an equal amount of positive charge is left on the opposite surface. This is shown in the figure.
The induced charges produce an internal electric field $\vec{E}_{in}$ inside the conductor in the direction opposite to the external electric field.
When the external electric field and the internal electric field become equal in magnitude, the net electric field inside the conductor becomes zero, and the charges stop depositing on the surface.