Explain the polarization of a nonpolar molecule in a uniform electric field and define linear isotropic dielectrics.

(N/A) As shown in the figure,in an external electric field,the positive and negative charges of a nonpolar molecule are displaced in opposite directions.
The displacement stops when the external force on the constituent charges of the molecule is balanced by the restoring force (due to internal fields in the molecule).
The nonpolar molecule thus develops an induced dipole moment in the direction of the field.
Linear isotropic dielectrics: Substances for which the induced dipole moment is in the direction of the field and is proportional to the field strength are called linear isotropic dielectrics.
The induced dipole moments of different molecules add up,giving a net dipole moment to the dielectric in the presence of the external field.