(1) Coulomb : It is a quantity of electricity obtained when one ampere current flows for one second.
It is the unit of quantity of electricity.
Q = I × t Coulomb (C)
Where Q is the charge or quantity of electricity in coulombs.
(2) Ampere : It is a strength of an electric current obtained when one coulomb of electricity is passed through a circuit for one second.
∴ I = Q/t
(3) Volt : It is the potential difference between two points of an electric conductor required to send a current of one amphere through a resistance of one ohm.
∴ V = I × R
Where V is the potential difference in volts and R is the resistance of a conductor in ohms.
(4) Joule : It is the electrical work or energy produced when one coulomb of electricity is passed through a potential difference of one volt.
∴ Electrical work = Q × V J
Where Q is electrical charge in coulombs and V is the potential difference.
(5) Ohm : It is the resistance of an electrical conductor across which when potential difference of 1 volt is applied, a current of one ampere is obtained. It has units, Ω or per siemens.
