Ohm’s Law – Simple Explanation with Formula and Example

Ohm’s Law is one of the most important and basic laws in electronics. It shows the relationship between Voltage (V), Current (I), and Resistance (R) in an electrical circuit. This law helps us calculate any one of these values if the other two are known.

📘 What is Ohm’s Law?

Ohm’s Law states that:

The current flowing through a conductor is directly proportional to the voltage applied across it and inversely proportional to its resistance.

In simple words:

More voltage → more current
More resistance → less current

📐 Ohm’s Law Formula

Ohm’s Law formula is:

V = I × R

From this formula, we can also calculate:

I = V / R

R = V / I

Where:

V = Voltage (Volt)
I = Current (Ampere)
R = Resistance (Ohm)

🔺 Ohm’s Law Triangle


      V
   -----
    I   R
Using the triangle:
Cover V → V = I × R

Cover I → I = V ÷ R

Cover R → R = V ÷ I

🧮 Example of Ohm’s Law

Example 1:

A resistor of 10Ω is connected to a 5V battery.
Find the current.

I = V / R
I = 5 / 10
I = 0.5 A

So, the current flowing is 0.5 Ampere.

Example 2:

A circuit has a current of 2A and a resistance of 4Ω.
Find the voltage.

V = I × R
V = 2 × 4
V = 8 V

So, the voltage is 8 Volts.

⚡ Applications of Ohm’s Law

Ohm’s Law is used to:

Design electrical and electronic circuits
Select proper resistor values
Calculate current in LED circuits
Troubleshoot faulty circuits
Study electronics in schools and colleges

❗ Limitations of Ohm’s Law

Ohm’s Law is valid only for:

Metallic conductors
Constant temperature

It does not apply to:

Diodes
Transistors
Semiconductors
Non-linear devices

📝 Conclusion

Ohm’s Law is the foundation of electronics. By using simple formulas, we can easily find voltage, current, or resistance in any basic circuit. Every electronics student and beginner must understand Ohm’s Law before learning advanced topics.

Basic Electronics for Beginners

Translate