current

                                                                    current

   Electricity is the flow of free electrons in a conductor from one atom to the next atom in the same general direction

. This flow of electrons is referred to as current and is

designated by the symbol “I”.  Electrons move through a conductor at different rates and electric current has different values

Current

that pass through

a cross-section of a conductor

is determined by the number of electrons 

in one second

current is measured in amperes which is abbreviated

“amps”. The letter “A” is the symbol for amps.

                  Units of Measurement

Prefix                   Symbol               Decimal

1 kilo ampere           1 k A                  1000 A

1 milli ampere          1 m A                  1/1000 A

1 micro ampere         1 µ A               1/1,000,000 A

current (I) =change in charge / change in time = dQ/dt

current measured by ampere . 1 Ampere = Coulomb /second

there are two types of current direct current (DC) and alternating current (AC)

DC is constant direction the flow of electrons in one direction

only .electrons flow from negative terminal to positive terminal

one the battery

                     I (DC) = Q/t

    AC change it`s polarity at half cycle and direction of 

electrons

                             I(AC)  =dQ/dt