A dielectric with polar molecules also
develops a net dipole moment in an
external field, but for a different reason In the absence of any external field, the
different permanent dipoles are oriented
randomly due to thermal agitation; so
the total dipole moment is zero When
an external field is applied, the individual dipole moments tend  to align
with the field When summed overall the molecules, there is then a net
dipole moment in the direction of the external field, i