Electricity works because of voltage and current.
Both are basic parts of any electric circuit.
Voltage gives energy.
Current shows how much charge is flowing.
They are related but not the same.
Let us understand both in simple words.
What is Voltage?
Voltage is the electric force or pressure.
It pushes electrons to move in a wire.
It is also called Electric Potential Difference.
Symbol: V
Unit: Volt (V)
Measured using a Voltmeter.
Example:
A 9V battery gives 9 volts of electric pressure.
Formula:
V = I × R
where,
- V is the voltage in volts
- I is the current in amperes
- R is the resistance in ohms
What is Current?
Current is the flow of electric charge.
It tells how many electrons pass in one second.
Symbol: I
Unit: Ampere (A)
Measured using an Ammeter.
Example:
If 1 coulomb of charge passes in 1 second then the current is 1 ampere.
Formula:
I = V / R
where,
- I is the current in amperes
- V is the voltage in volts
- R is the resistance in ohms
Voltage Vs Current Explained through Graph Diagram:
This graph diagram above shows relation between voltage and current.
The straight blue line is for Ohmic conductor like resistor.
It means voltage and current increase equally.
The red curved line is for Non-Ohmic conductor like bulb.
It means current does not increase in same way with voltage.
So, when voltage goes up, current goes up too but differently for each conductor.
Difference Between Voltage and Current:
| Feature | Voltage | Current |
|---|---|---|
| Meaning | Electric pressure or potential difference | Flow of electric charge |
| Symbol | V | I |
| Unit | Volt (V) | Ampere (A) |
| Device used | Voltmeter | Ammeter |
| Position in circuit | Connected in parallel | Connected in series |
| Nature | Causes current to flow | Result of voltage |
| Example | Battery gives 12V | Bulb takes 2A current |
Relationship Between Voltage and Current:
Voltage and current are connected by Ohms Law.
If voltage increases then current also increases (for same resistance).
If resistance increases then current decreases.
Ohms Law Formula:
V = I × R
Example:
If voltage = 12V and resistance = 6Ω
then current = 12 / 6 = 2A
So for higher voltage requires more current.
More resistance means less current.
Conclusion:
Voltage and current are the heart of electricity.
Voltage pushes the charge.
Current shows the movement of charge.
They work together in every circuit.
Without voltage, current cannot flow.
Understanding their relationship helps in all electrical studies and devices.