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OHM's Law with Examples.

OHM's Law

If you have studied till intermediate level or studying currently in those standards so you will be aware of the terms like what is current, resister, voltage and circuits. Our todays center of interest is to explain what are these parameters and components and how Ohm's law explain their relationship.

Current can be explained as the flow of charge in a conductor from one place to another. This is similar to the flow of water in a water tube. While the resistor is a component which resists the flow of current in the conductor. Voltage is opposite to the resister which pushes the current to flow in the conductor. The unit of voltage is volt, current is ampere and resistor is OHM.

what is circuit?

It is a pathway or closed loop in which the current is moving from positive terminal to the negative terminal. for a complete working mechanism of the circuit it is important that the circuit is closed. A circuit consist of many electrical components like resister, battery, load, transistor, capacitor and inductor etc.


An Electrical Circuit

The simplest form of electrical circuit will at least consist of voltage, resistance and current. All these three components or parameters are related to each other in Ohm's Law.

Ohm's Law

It is a formula which is used to measure the relationship between Current, Voltage and Resistance.


When we are going to find any one of the three parameter in the presence of other two parameters so we use Ohm's Law in those circumstances. for example, if voltage and resistance of a specific circuit are known to us so we can find current of the circuit through Ohm's law formula.


V=I×R or Voltage = current × resistance or Volts = ampere × ohm's

This formula is modified for finding different parameters:

for resister: R=V/I

for current I=V/R

Simply we can explain Ohm's law as the flow of electron/charge in a conductor will decrease with the increase of resistance.

Now I will explain Current, voltage and resistance through proportionalities for your better understanding.

Voltage is directly proportional to current while inversely proportional to resistance.

Current is directly proportional to voltage while inversely proportional to resistance.

Let's do an example on Ohm's law so that you know how to solve problems related to voltage, current and resistance.

Example 01: Find the current of the circuit when the voltage of the circuit is 15 volt with 4 Ω resistance.

Given data:

Voltage = 15 volts

Resistance = 4Ω


Current = ?


The formula of Ohm's Law is


Modify the formula for current


Putting values,


I=3.75 A.

It means that the current flowing through the circuit is 3.75 A.

Example 02: suppose that we have a circuit with a resistance of 80 Ω and a current of 4 ampere is flowing through it. Find the voltage of the circuit.

Given data:

Current = 4 ampere

Resistance = 80Ω


Voltage = ?


The formula of Ohm's Law is


Putting values,

V= (4)(80)

V= 320 volt

It means that the Voltage of the circuit is 320 V.

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