Magnetic Effect of Current

The Magnetic Effect of Current is a physics demonstration apparatus used for showing that an electric current produces a magnetic field around a conductor. It helps students, physics teachers and laboratory instructors observe compass deflection, field direction, current reversal and the relationship between electricity and magnetism through one supervised setup.

Product Description

The STEMAids Magnetic Effect of Current apparatus provides a practical demonstration of the magnetic field created by a current-carrying wire. A conductor is positioned near one or more magnetic compasses or another suitable field indicator and connected to a controlled low-voltage electrical source.

When current flows, the compass needle deflects from its normal north–south alignment because it responds to the combined magnetic field of Earth and the conductor. Reversing the current reverses the field direction and changes the direction of deflection. The exact conductor geometry, compass arrangement and electrical limits must be confirmed from the current STEMAids specification.

Key Features

• Demonstrates the magnetic effect of current: Shows that electricity flowing through a conductor generates a magnetic field.
• Provides visible compass deflection: Converts an otherwise invisible magnetic field into an observable response.
• Shows field direction: Supports application of the right-hand grip rule around a straight conductor.
• Demonstrates current reversal: Shows that reversing current reverses the magnetic-field direction.
• Supports current comparison: May allow learners to compare compass deflection at different permitted current levels.
• Introduces electromagnetism: Connects electric circuits with electromagnets, relays, motors and solenoids.
• Suitable for laboratory instruction: Supports classroom demonstrations, practical activities and science exhibitions.

Technical Specifications

What’s Included in the Kit

• Mounted straight conductor or current path
• Magnetic compass or compass set
• Base, supports and electrical terminals
• Switch or current-reversal connector
• Connecting leads and protective resistance
• Experiment instructions and circuit diagram

Applications and Uses

• Demonstrating magnetic fields produced by electric current.
• Observing compass deflection near a conductor.
• Applying the right-hand grip rule.
• Investigating the effect of reversing current direction.
• Comparing magnetic response at different current levels.
• Introducing electromagnets, solenoids and electric motors.
• Supporting physics practicals and science exhibitions.

How to Use the Magnetic Effect of Current Apparatus

1. Place the apparatus on a stable surface away from magnets and steel objects.
2. Allow the compass needle to settle along the local north–south direction.
3. Position the conductor as specified relative to the compass.
4. Connect only the approved low-voltage power source.
5. Close the circuit briefly and observe the compass deflection.
6. Open the circuit and allow the needle to return to its initial position.
7. Reverse the current using the approved switch or terminal arrangement.
8. Repeat the observation and compare the two deflection directions.

Safety and handling: Never connect an unverified power supply or short-circuit the source. Conductors and resistors may heat under excessive current. Energise the apparatus only for the permitted duration and disconnect power before changing connections.

Care & Maintenance

• Disconnect power before cleaning or inspecting the apparatus.
• Keep compass needles away from permanent magnets during storage.
• Inspect conductor insulation, terminals and leads for damage.
• Store the apparatus in a dry cabinet after all components have cooled.

Why Choose STEMAids

STEMAids develops educational models, experiment kits and laboratory resources for practical science instruction. Buyers can explore related physics laboratory products, educational science models, STEM learning kits and the complete scientific and educational product range. Request the current conductor arrangement, compass quantity, electrical rating, component list and operating instructions before procurement.

Frequently Asked Questions

What is the Magnetic Effect of Current apparatus used for?

It is used to demonstrate that electric current flowing through a conductor produces a surrounding magnetic field.

Why does the compass needle deflect?

The needle aligns with the combined magnetic field produced by Earth and the current-carrying conductor.

What happens when the current is reversed?

The conductor’s magnetic-field direction reverses, causing the compass needle to deflect in the opposite direction.

What is the shape of the field around a straight wire?

The magnetic field forms concentric circular paths centred on the current-carrying wire.

Does a larger current produce a stronger magnetic field?

For the same conductor arrangement and observation distance, increasing current increases the magnetic-field strength.

What voltage does the apparatus require?

The electrical rating is not publicly verified. Use only the voltage and current specified for the supplied STEMAids apparatus.

Explore more physics laboratory apparatus from STEMAids for electricity, magnetism and electromagnetic experiments.

Recommended primary image ALT text: Magnetic Effect of Current apparatus with straight conductor, compass and electrical terminals.

Recommended detail image ALT text: Compass needle deflecting near a current-carrying wire during an electromagnetism experiment.

Recommended application image ALT text: Students demonstrating the magnetic effect of electric current in a supervised physics laboratory.