Chapter 20.2, Problem 23SSC

To determine

To explain: The reason for smaller value of electrostatic force than expected from Coulomb’s law, between the given spheres.

Explanation of Solution

Introduction:

The electrostatic force is the force of attraction or repulsion between the electrically charged particles. The electrostatic force between the two charges $q_A$ and $q_B$ separated by a distance $d$ is given by Coulomb and can be written as,

  $F\text{ = K}\frac{q_A{q}_B}{d^2}$

Where $\text{ K}$ is a constant, $\text{ K}=9\times {10}^9\text{ N}{\text{.m}}^2/C^2$

A small positively charged plastic sphere is brought closer to large positively charged metal sphere. Due to this, the plastic sphere exerts opposing force on some of the charges in the metal sphere and repelled to its opposite side. Then the distance between the charges are greater than that between the centers of the two spheres. This results in reduction in the value of electrostatic force than that expected from Coulomb’s law.