Current Electricity PDF

What is the electric current?

The constant flow of charged particles in a circuit is called an electric current. The flow of electric current flow is from higher electric potential to lower electric potential. The movement of an 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

Electric Current
Experiment: Circuit

Below is a simple circuit to show the flow of current.

Electric 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, the load is used and cell as a power source.

George Simon Ohm shows the relationship between the voltage, resistance and current and it is known as Ohm’s law. 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

Practise This Question

If a light ray from air enters three different media in such a way that the refracted angles are 450, 300 and 600 respectively, Identify the right statement with respect to their density.

In the figure, n1  represents refractive index of air.