What is electric current?
The constant flow of charged particles in a circuit is called electric current. The flow of electric current flow is from higher electric potential to lower electric potential. The movement of electron in the current flow is opposite to electric current. Below is the difference between AC and DC current
- Direct current (DC): Here the flow of electric charge happens only in one direction. Used in cell phone, flashlights etc.
- Alternating current (AC): Unlike DC the flow of electric charge changes direction periodically. Example: The current supplied to offices and houses.
Below is the graph showing the flow of electric charge in AC and DC
Below is a simple circuit to show the flow of current.
The circuit is made of copper wire, switch board, bulb and power source.
When the switch is closed the current flows and the bulb glows. Once the switch is open the flow of current is stopped. To avoid short circuit, load is used and cell as power source.
Ohm’s law formula by George Simon Ohm shows the relationship between the voltage, resistance and current. This law is the basis of electricity
V = I R
Where V is the voltage in volts and it measures the difference the electrical energy between 2 points on a circuit
I is the current in amps and is the count of electrons passing a particular point per second
R is the resistance in ohms and controls the flow of electric current
Therefore, R = V / I and I = V / R
To learn more download Current electricity pdf