Electric Current
What is an electric current?
An electric current is a flow of charge. In
a metal or a wire, the electric current charge is carried by
conduction of electrons which are not attached to any given
fixed ion of the metal.
What is the unit of electric current?
The unit of electric current is the
ampere. The definition of the ampere is given
below.
One ampere is the constant current that if
maintained in tow parallel conductors of infinite length, of
negligible circular cross section and placed 1 m apart in a
vacuum, would product between those conductors a force of 2 x
10 ^{7} N per meter length.
What is a coulomb (C)?
A coulomb (C) of electric charge is the
charge which passes a given point when 1 ampere of steady
current flows for 1 second. Therefore, a steady current of 3
Ampere for 5 minutes means that a charge of 3 x 5 x 60 = 900 C
has been passed in total. The link can be expressed in the
formulas and equations below. t is time.
Charge Q
Current I
