Eddy Current Pendulum 1 - Physics Demonstrations - Eddy Current Pendulum 1 | Physics Undergraduate Labs

Radar magnets produce strong magnetic fields that can damage electronic devices, credit cards, and magnetic storage media. Keep these items at least 30 cm away from the magnets. The magnets can also pinch fingers if allowed to snap together—handle carefully and never place fingers between pole pieces.

Purpose

Solid and slotted conducting plates swing through magnetic fields simultaneously. The solid plate stops almost immediately due to eddy current damping; the slotted plate swings freely. A striking demonstration of Lenz's law and magnetic braking.

Eddy current pendulum: solid copper plate (left) and slotted copper plate (right) hanging from rods on a horizontal crossbar, with two black radar magnets on the bench below

Close-up of the copper plates mid-swing between the radar magnets, with motion blur visible on both plates

Figure 1: Complete eddy current pendulum setup with solid plate (left) and slotted plate (right) suspended between two radar magnets.

Figure 2: Close-up of the plates swinging between the radar magnet poles. The solid plate (left) stops quickly while the slotted plate (right) continues to swing.

Safety Warnings

Warning: Strong Magnetic Fields

Purpose