GCSE Physics Tutorial: Demonstrating the Magnetic Field Effect of a Current

The magnetic field effect of a current is a fascinating phenomenon that showcases the interplay between electricity and magnetism. This tutorial will guide you through a simple and engaging experiment to demonstrate the magnetic field effect of a current.

Materials Needed:

1. Battery (e.g., AA battery)

2. Insulated wire (about 1 meter)

3. Iron nail or paperclip

4. Small compass (magnetic needle)

5. Cardboard or wooden board

6. Masking tape or adhesive putty

Experiment Steps:

1. Prepare the Setup:

   • Attach the cardboard or wooden board to a table using masking tape or adhesive putty.

   • Place the iron nail or paperclip on the board.

   • Attach the small compass to the other end of the board.

2. Create the Circuit:

   • Strip the ends of the insulated wire to expose the metal.

   • Connect one end of the wire to the positive terminal of the battery.

   • Connect the other end of the wire to the iron nail or paperclip to form a closed circuit.

3. Observe the Compass:

   • Place the setup on the board so that the compass is near the iron nail or paperclip.

   • Observe the behaviour of the compass needle as you complete the circuit by touching the wire to the battery terminal.

   • Observe the direction in which the compass needle moves.

Explanation:

When the circuit is completed by connecting the wire to the battery terminal, an electric current flows through the wire. This electric current generates a magnetic field around the wire according to Ampère's law. The magnetic field lines form circular loops around the wire.

As the compass needle is a small magnet, it aligns itself with the local magnetic field. When the current flows through the wire, the magnetic field around the wire interacts with the magnetic field of the compass needle, causing the needle to move. The direction of the needle's movement is determined by the direction of the magnetic field lines around the wire.

Observations:

You will observe that the compass needle deflects or moves when the circuit is completed. The direction of the needle's deflection will depend on the orientation of the wire and the direction of the current flow.

Conclusion:

This experiment demonstrates the magnetic field effect of a current. By completing a circuit using a battery and wire, you create a magnetic field around the wire, which interacts with the magnetic field of a nearby compass needle. The movement of the compass needle confirms the presence of the magnetic field and provides a tangible example of the connection between electricity and magnetism.

Looking for a more dynamic learning experience?
Explore our engaging video lessons and interactive animations that GoPhysics has to offer – your gateway to an immersive physics education!