Electric Current Formula

Today at the flick of a switch or turn of a knob we are having instant power. This is possible due to the electric current. It is one of the important discoveries that helped us to revolutionize our way of living. From the time we wake up till night, our life is fully dependent on electricity. Electricity represents the follow of electric current. Electric current is known as the rate of flow of negative charges of the conductor. It means the continuous flow of electrons in an electric circuit is called an electric current. In this article, we will discuss this important concept of an electrical circuit and electric current formula with examples. Let us begin learning!

Electric Current Formula

What is the Electric Current?

The conducting material consists of a large number of free electrons which is moving from one atom to the other at random. When the potential difference is applied across a wire, then loosely attached free electrons will start moving towards the positive terminal of the cell.

This continuous flow of electrons makes the existence of the electrical current. Therefore the flow of currents in the wire is from the negative terminal to the positive terminal through the external circuit.

This traditional flow of current is so firmly established that it is still in use. Thus, the conventional direction of the flow of the electric current is from the positive terminal of the cell to the negative terminal of the cell through the external circuit.

On the basis of the flow of electric charge, the current can be classified into two types, which are alternating current and direct current. In direct current, the charges flow in one direction but in alternating current, the charges flow in both the direction.

The Formula for Electric Current

The magnitude of the flow of current at any section of the conductor is defined as the rate of flow of electrons.

Mathematically, this can be represented as:

I = \( \frac{Q}{t} \)

Where,

I	Electric current
Q	Electric Charge
T	Time

Electric current is the rate of change of electric charge through a circuit. This electric current is related to the voltage and resistance of the circuit. Using Ohm’s law, we can represent as the formula:

I= \( \frac {V}{R} \)

Where,

V	Electric Voltage
R	The resistance of the metallic wire
I	Electric Current

Since we measure the charge in coulombs and time in seconds, therefore the unit of electric current is coulomb/Sec or amperes. The amperes is the SI unit of the electric current. The symbol for electric current is I. Thus, an electric wire is said to carry a current of 1 ampere when charge flows through it with the rate of one coulomb per second.

Solved Examples on Electric Current Formula

Q.1: Calculate the electric current passing through the circuit in which the voltage and resistance be 25V and 5 \( \omega\)  respectively?

Solution:

V = 25 V

R = \( 5 \omega \)

Here, we have to apply ohm’s law formula.

The equation for the electric current using Ohm’s law is,

I= \( \frac {V}{R}\)

Putting the known values, we get

I = \( \frac {25}{5} \)

I= 5 A

Thus the value of electric current is 5 A.