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Ohms Law Formula

Electricity is the flow of charge in a conductor material. Electricity is possible due to the flow of current in the conductor. This current flow is depending on the resistance of the wire and the potential difference between the two endpoints. This relationship was given first by Ohm. He gave the Ohm’s law which is very popular in the field of electricity of Physics. Using Ohm’s law we can determine either voltage, current or impedance or resistance of the electric circuit. It is possible when the other two quantities are known to us. It also makes power calculations simpler. In this topic, we will discuss the Ohms law formula with examples. Let us begin learning!

Ohms Law Formula

Ohms Law Formula

Concept of Ohms Law

Electricity has as many applications in our day to day life. It is an essential tool that provides power to electrical devices to our electrical appliances. Therefore, we can say that the flow of charge builds up the current which we are calling as Electricity.

A very basic law regarding the flow of currents I Ohm’s Law. The concept of resistivity and conductivity both are interrelated and can be computed with the help of others. Also, the power of electricity can be computed easily. The work is done per unit charge by the source while taking the charge from lower to higher potential is called the electromotive force, or emf, of the source.

Ohms law says that the current running through the conductor is directly proportional to the potential difference across its endpoints. It also depends on the temperature and other physical conditions are constant. Ohm’s law formula i.e. potential difference formula is used to calculate the Resistance, Current as well as Voltage.

The formula of Ohm’s Law

If the physical conditions of a conductor like a temperature remain unchanged, then the electric current flowing through the conductor is directly proportional to the potential difference applied across two ends.

\(I\propto V\)

i.e.  V = \(R \times I\)

Where the constant of proportionality i.e. R is giving the value of resistance of the conductor.

Electrical Resistance

It is the obstruction offered by any conductor in the path of flow of current is called its electrical resistance. Electrical resistance, i.e., R will be

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

Its SI unit is ohm and denoted as \(\Omega\).

The ohms law can also be termed as following to provide the Current Formula:

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


I Current
V Voltage
R Resistance

 Solved Examples

Q.1: Find out the amount of current flowing through the electric heater having a voltage of 220 V and resistance is 10 \(\Omega\).


As given in the problem:

Resistance R = 10 \(\Omega\)

Voltage V = 220 V

The current formula is below:

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

I= \(\frac {220}{10} \)

I = 22 A

Therefore the amount of current flow is 22 A.

Q.2: Find the resistance of an electrical circuit which has the voltage supply of 10 Volts and current of 0.005 A.

Solution: Given values are:

V = 10 V, I = 0.005 A

Formula for resistance,

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

R= \(\frac { 10 }{ 0.005 }\)

R = 2000 \(\Omega\)

Thus resistance will be 2000 \(\omega\).

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