Q.Explain dielectrics in detail and how an electric field is induced inside a dielectric.

Step 1. What a dielectric is. A dielectric has no free charges; every electron remains bound within its own atom or molecule (examples: glass, mica, ebonite).

Step 2. Non-polar molecules. In molecules whose positive and negative charge centres normally coincide, an applied field displaces the two centres apart by a tiny distance, inducing a small dipole moment aligned with the field.

Step 3. Polar molecules. In molecules that already possess a permanent dipole moment (e.g. water) but are normally randomly oriented by thermal motion, the applied field exerts a torque ($\tau=pE\sin\theta$) that partially aligns them, giving a net polarisation.

Step 4. Induced internal field. The resulting polarised material -- filled with a huge number of roughly aligned dipoles -- produces its own internal field that points opposite to the applied external field $E_o$, since the aligned dipoles' own field opposes the field that caused the alignment. …

Distinguish the non-polar (induced dipole) and polar (aligned dipole) mechanisms of polarisation, then explain why the resulting indu …

• Claiming the field inside a dielectric becomes zero, as it does inside a conductor -- a dielectric's induced field only partially cancels the applied …