Mention the SI unit and value of fundamental charge. Write its smaller units.

Explanation

Electric charge of electron is called fundamental charge. Its symbol is e and charge is negative.
In the international system (SI) of units, a unit of charge is called a coulomb and is denoted by the symbol C.
One coulomb is the charge flowing through a wire in 1 s if the current is 1A (ampere).
In this system, the value of the basic unit of charge is, `e = 1.602192 xx 10^(-19)` C. In general it is taken as e = `1.6 xx 10^(-19)` C.
There are about `6.25 xx 10^18` electrons in a charge of - 1 C.
In electrostatics, smaller charges are :
1 mC (milli coulomb) = `10^(-3)` C
`1 muC` (micro coulombs) `=10^(-6)` C
1nC (nano coulombs) `=10^(-9)` C