Electric Currents in Conductors

Electric Current and Resistance

Electric current is defined as the rate of flow of electric charges across any cross-section of a conductor. If dq coulombs of charge flow across any cross-section of a conductor in time dt, then the magnitude of the current I flowing through it is given by:

S.I unit of current is Ampere and is denoted as A.

1 A = 1 C/ 1s

1 mA = 10^-3 A,

1 μA = 10^-6 A

• The direction of electric current by convention is taken to be direction of flow of positive charges.
• In electrolytes, ions act as charge carriers.

The amount of charge flowing from