Question

What is dielectric substance?

Answer 1

Dielectric substances are the kind of substance which generates an additional induced electric field when it comes in the influence of some external magnetic field. The direction of this induced electric field is in the opposite direction of the direction of the external electric field.

Complete step by step answer:
When these substances come under the influence of some external electric field then they will go through the phenomenon of the polarisation.
Polarisation is the phenomenon which tells us the behaviour of the material when it comes in contact or influence of the external electric field. When the dielectric material is influenced by some external electric field then the separation of the different types of charges happens and accumulation of similar types of charges takes place inside that substance. This produces a polarity in the substance and the substance behaves like a polar material having two different poles which can attract the opposite charges separately.
So now this polarisation of the material will result in the formation of the induced electric field by the dielectric material.

So, the dielectric substance is the substance which produces an induced electric field (due to polarisation) under the influence of some external electric field.

Note: -The phenomenon of the polarisation can be understood by the example of the capacitors having dielectric substance in between the plates of the capacitor. When the electric current flows through the capacitor then plates of the capacitor acquire charges of different signs then an electric field is produced in between the plates and the dielectric substance present in between the plates gets polarised and produces another electric field known as induced electric field.