Question

A charge ‘Q’ is uniformly distributed on the surface of a spherical conductor. In order to calculate the Electric field because of it, one has to take infinitesimal elements of charges and integrate. This is because

• A. Electrostatic force between two charges is a central force.
• B. Electrostatic force is dependent upon the medium in which the charges are located.
• C. Electrostatic force can only be utilized for point charges.
• D. Electrostatic force varies with inverse of distance squared.

Answer 1

The correct option is C

Electrostatic force can only be utilized for point charges.

Electrostatic force between two charges at restis given by Coulomb’s law. Coulomb’s law is valid only for point charges. In order to calculate the net field due to a continuous charge distribution at any point,

1. We need to choose infinitesimal elements,
2. Treat them as point charges and
3. Calculate electrostatic force.

Integration is used to add the fields due to all such charges.