Ohm’s Law Calculator Tool:An Ohm’s Law Calculator is a tool used to calculate the relationship between Voltage (V), Current (I), and Resistance (R) in an electrical circuit.
Ohm's Law Virtual Circuit
5 Ω
ON/OFF
Ammeter
Current (I): 0 A
Voltmeter
Voltage (V): 0 V
What is an Ohm’s Law Calculator Tool?
An Ohm’s Law Calculator is a tool used to calculate the relationship between Voltage (V), Current (I), and Resistance (R) in an electrical circuit.
It is based on the formula: V=I×RV = I \times RV=I×R
Meaning:
- V = Voltage (Potential Difference)
- I = Current (flow of electric charge)
- R = Resistance (opposition to current)
This tool helps users understand how changing resistance or voltage affects the current in a circuit.
Who Can Use This Tool?
| User | Why It Helps |
|---|---|
| Students (School/College) | To learn and verify Ohm’s Law practically. |
| Teachers | To demonstrate electrical concepts in class. |
| Electricians / Technicians | To calculate correct values before working on circuits. |
| Engineering & Science Learners | To design or test circuits safely. |
| DIY Electronics Hobbyists | To avoid wiring mistakes and burnouts. |
Basically, anyone learning or working with electricity can use it.
How to Use the Tool (Step-by-Step)
- Set the Battery Voltage (usually between 0–10 Volts).
- Adjust the Rheostat (Variable Resistor) using the slider.
- Turn the Switch ON.
- Click Calculate.
- The tool will show:
- Ammeter reading → How much current is flowing (0–10 A scale).
- Voltmeter reading → How much voltage is across the resistor.
- You can change the rheostat again and observe the needle movement in both instruments.
- Click Reset to start fresh.
What Does This Demonstrate?
As you increase resistance:
- Current decreases
- Voltmeter drops
- Ammeter needle moves down
As you decrease resistance:
- Current increases
- Voltmeter rises
- Ammeter needle moves up
This directly proves Ohm’s Law: I∝V(Current increases when Voltage increases if Resistance is constant)I \propto V \quad \text{(Current increases when Voltage increases if Resistance is constant)}I∝V(Current increases when Voltage increases if Resistance is constant)
Simple Example
If:
- Voltage = 6 Volts
- Resistance = 3 Ohms
Then: I=VR=63=2 AmperesI = \frac{V}{R} = \frac{6}{3} = 2 \text{ Amperes}I=RV=36=2 Amperes
So the ammeter needle will point to 2A.

