Those material objects that do not allow charge to pass through them are known as Insulators or non-conductors.
Those material objects that allow the charge to pass through them are called conductors.
3. Semi Conductors
Those material objects that allow some charge to pass through them are called Semi-Conductors.
4. Free Electron
Those electrons that are loosely bound by their atom and can move freely within the material are called free electrons.
The medium or space (vacuum) between two charges is said to be dielectric.
6. Force of Attraction
When two charges attract each other the force is called force of attraction. It has a negative sign.
7. Force of Repulsion
When two charges repel each other the force is called force of repulsion. It has a positive sign.
8. Equivalent Resistance
The relative resistance that has equal value to the combined value of a resistor of a circuit is called equivalent resistance. It is denoted by R(E).
9. Direct Current
Such a current that does not change its direction is known as direct current. It is denoted by DC, which is obtained from primary and secondary cells.
10. Alternating Current
Such a current that reverses its direction with a constant frequency from positive to negative and negative to positive direction is known as Alternating Current, obtained by generators. It is denoted by AC.
11. Conventional Current
An electric current considered to flow from points at positive terminal potential to points at negative potential.
12. Primary Cell
A voltaic cell in which the chemical reaction that produces the e.m.f is not reversible is known as Primary Cell.
13. Secondary Cell
An electric cell that can be changed by passing an electric current through it is called Secondary Cell. The chemical reaction in this case is reversible.
14. Fused Plug
It is a wired plug,