By Danny Donahue, Updated Mar 24, 2022
Magnetic fields permeate the cosmos, enveloping planets, stars, and galaxies. Earth's magnetic shield protects us from solar radiation and creates the stunning auroras near the poles. In this guide, you'll learn how to generate a magnetic field in a compact setup and gain insight into the behavior of magnetic forces on a small scale.
Begin by winding the insulated copper wire around the iron bar, maintaining a consistent, tight coil. Ensure you wind in a single direction, as the coil orientation determines the field direction. Leave a short, uncoiled length (~2 ft) at each end for connection.
Remove approximately 3 inches of insulation from each end of the wire. Form the exposed conductors into loops that will fit snugly onto the battery terminals.
Secure the loops onto the battery terminals, connecting the negative terminal first. Once connected, test the field by bringing small ferromagnetic objects—such as nails—close to the bar to observe the magnetic attraction.
Place the battery on a piece of cardboard or wood instead of concrete, as concrete can cause the battery to discharge prematurely.
