ELECTRIC CURRENT

 

DEFINITION OF ELECTRIC CURRENT

Electric current is defined as the amount of charge flowing through a particular area in a unit of time (Rate of flow of electric charges is known as electric current)

SI unit of electric current is ampere or amp (A)

EQUATION TO FIND ELECTRIC CURRENT IN TERMS OF CHARGE AND TIME 

Since electric current is the rate of flow of charges 

Current (I)= charge (q)/time (t)

I=q/t

(NOTE:- Charge present in matters around as (in their atoms) electrons (-ve charge) and

protons (+ve charge). 

But only the substance having free electrons is able to conduct electricity, they are known as conductors. And substance that does not have free electrons do not conduct electricity they are called insulators)

DIRECTION OF FLOW OF ELECTRIC CURRENT

The direction of electric current is taken as directly opposite to the direction of flow of electrons. (since electrons were not discovered at the time when electric current was first observed, the direction of electric current was taken as the direction of flow of positive charge) 

INSTRUMENT USED TO MEASURE ELECTRIC CURRENT 

An ammeter is an instrument used to measure electric current in a circuit. It should be always connected serious with the resistance or load while measuring.