Ampere is a SI (International System) unit of electric current. It is represented by the symbol A.
Ampere is named after a French mathematician and physicist André-Marie Ampère, who is also known as the Father of Electrodynamics.
Ampere measures of rate of flow of electron or electric current in an electrical conductor.
One ampere represents the movement of one coulomb of charge per second at a given point of an electric circuit. An ampere can be mathematically represented as,
1 A = 1 C/S
where coulomb is SI unit of charge, 1 coulomb = 6.241×1018 electrons.
One ampere is also the amount of electric current generated in an electrical circuit with a electric resistance of 1 ohm, when a electric potential of 1 volt is applied. Thus, this can be mathematically expressed as
I(A) = R(Ω)/ V(V)
In the above equation I represents the electric current in ampere, R represent electric resistance in Ohm and V represent electric potential in volts.
An electrical instrument that is used to measure electrical current in amperes is known as Ammeter or Ampere meter. In order to measure current, ammeters are attached to electrical circuits in series. Resistance of ammeter is almost zero, so it will not affect measured circuits.
There are various kinds of ammeters available to measure electric current such as Moving-coils ammeter, electrodynamic ammeters, moving-iron ammeters, hot-wire ammeters, digital ammeters, integrating ammeters and pico-ammeters.
