Electromagnets

Magnetic Field Lines We can represent the magnetic field around a wire or magnet using field lines.

Magnetic Field Lines The arrows show the direction a compass needle would point at that point in the field.

Field around a magnet

Moving charges (currents) Moving charges (electric currents) also produce a magnetic field Conventional current – electrons flow in the opposite direction

Magnetic field around a straight conductor Current OUT of page Current IN to page You can use the right hand screw rule to decide which direction the field goes

Electromagnets

Field around a solenoid

Field around a solenoid

Electromagnets

To make an electromagnet stronger The 3 C’s More Coils More Current Use an iron Core

The experiment You will make a simple electromagnet by wrapping insulated wire around an iron nail and connecting it to a 1.5 V cell. You will start with 100 turns and increase the number of turns by 50 at a time. For each measurement you will be testing how many paperclips the electromagnet can pick up. The more paperclips, the stronger the magnet is.

To do list: Title Prediction Equipment List Labelled diagram - use pencil!!! Procedure (bullet-pointed) Results Table (make room for repeats) - use pencil!!!