Question

The dielectric strength of impregnated paper is about

• A. $30\raisebox{1ex}{$kv$}\!\left/ \!\raisebox{-1ex}{$mm$}\right.$
• B. $20\raisebox{1ex}{$kv$}\!\left/ \!\raisebox{-1ex}{$mm$}\right.$
• C. $15\raisebox{1ex}{$kv$}\!\left/ \!\raisebox{-1ex}{$mm$}\right.$
• D. $5\raisebox{1ex}{$kv$}\!\left/ \!\raisebox{-1ex}{$mm$}\right.$

Answer 1

The correct option is A

$30\raisebox{1ex}{$kv$}\!\left/ \!\raisebox{-1ex}{$mm$}\right.$

Dielectric strength:

1. The dielectric strength of any material is a measure of the electrical strength of an insulator material present in it.
2. It may be defined as the maximum voltage, which is required to produce a dielectric breakdown across any material.
3. Its SI unit is Volts per meter or volts per millimeter.
4. Some examples of dielectric materials are listed below:
5. Solid Dielectrics – Commonly Ceramic, Plastic, Mica, and Glass. Dielectric Liquid is – Distilled Water. Dielectric Gas examples are – Dry Air, vacuum, nitrogen, and helium.

Impregnated paper:

1. It is a sheet with the best liquid-retaining and water-absorbing properties and it is made from natural cotton and wooden pulp.
2. It is very much possible to make this paper with a varying thickness of $0.5-1.0mm$ and a base weight of $300-500\raisebox{1ex}{$kg$}\!\left/ \!\raisebox{-1ex}{$m^2$}\right.$.
3. For most plastics, the dielectric strength is nearly $100-300\raisebox{1ex}{$kv$}\!\left/ \!\raisebox{-1ex}{$mm$}\right.$.
4. The dielectric strength of impregnated paper is nearly $30\raisebox{1ex}{$kv$}\!\left/ \!\raisebox{-1ex}{$mm$}\right.$.

Thus, the correct option is option A.