Question

what is meant by continuous charge distribution ? how do you apply superposition principle to obtain total force on a point charge due to n discrete charges and three continuous charge distribution.

Answer 1

Continuous charge distribution is the distribution of charge such that the elementary charge is closely packed homogeneously. The elementary charge cannot be considered individually in continuous charge distribution. It can be the packing of elementary charge in a linear fashion or on area or distributed in the volume.
When n number of discrete charges and 3 continuous charge distributions are there, the total point on a given charge is equal to the vector sum of forces due to individual charges and charge distribution.
For discrete charges, force on the point charge can be calculated individually by the formula of electrostatic force.
For continuous distribution of charges, we need to find the electric field at the given point due to the charge distribution and then find the force by F=qE where q is the magnitude of point charge and E is the electric field at that point. Find the electric field and force individually due to each charge distribution.