Electricity Feel the current that powers your world.

What is Electricity?

Electricity

Electricity is a form of energy created when electric charges move from one place to another.

Imagine charges flowing through a wire like water in a pipe, lighting bulbs and powering phones.

Electric Charge

Electric Charge

Matter carries either a positive (+) or negative (−) electric charge.

Key Characteristics:

  • Positive charge (+) is often shown in red.
  • Negative charge (−) is often shown in blue.
  • Like charges repel each other.
  • Opposite charges attract.

Try it:

Drag the + and − labels onto the red and blue spheres to check the attract–repel rule.

Electric Current

Electric Current (I)

Electric current is the rate at which electric charge passes a point each second.

Key Characteristics:

  • Symbol: I
  • Flow per second: \(I = \frac{Q}{t}\)
  • Unit: ampere (A)

Example:

6 C of charge in 3 s gives \(I = 2\text{ A}\).

Current Over Time

https://asset.sparkl.ac/pb/sparkl-vector-images/img_ncert/LyVgsA03X5zuWdHGOcwEhTqmpGGUx7Qkf65uB4Io.png

Reading a Constant Current

On a current-time graph, a horizontal line means the current stays exactly the same every second.

Key Points:

  • Flat line = constant current.
  • Slope zero shows no change over time.
  • Pick any point; current value is identical.

Build a Simple Circuit

Follow each step to list every part and see how a closed path makes the bulb glow.

1

Attach the Battery

Clip one end of a wire to the positive terminal of the battery.

2

Connect to the Bulb Base

Touch the free end of that wire to the metal contact at the bottom of the bulb holder.

3

Complete the Path

Use a second wire to link the bulb’s side terminal to the battery’s negative terminal, forming a closed path.

4

Watch It Glow!

Current flows through the closed circuit—battery → wire → bulb → wire—so the bulb lights up.

Pro Tip:

Even a tiny gap breaks the closed path and stops the current—check all connections if the bulb stays dark.

Multiple Choice Question

Question

Which action allows electric current to start flowing in a simple circuit?

1
Close the switch to complete the path
2
Add thicker insulation around the wire
3
Remove the battery from the holder
4
Keep the switch open

Hint:

Current needs a continuous path to travel.

Key Takeaways

Electricity recap and what comes next.

1

What is electricity?

Energy transferred by moving electric charges.

2

Charge basics

Two kinds: positive and negative; like repels, unlike attracts.

3

Current

Rate of charge flow; measured in amperes \( (A) \).

4

Closed circuits

Current flows only through an unbroken conducting loop.

5

Source of push

A cell supplies potential difference that drives the charges.

6

Next step

Up next: link voltage, current & resistance using Ohm’s law.