Demonstration Manual

Electricity and Magnetism

DEM80 - Jumping Cow Magnet Demo

Objective:

- To use a solenoid to launch a magnet into the air.

Apparatus:

• Circuit-Test PSB-330T Supply set to 15V D.C.
• Variac set to 70 V A.C.
• lab stand and clamp
• solenoid
• cow magnet
• DEM80 pulse generator and full bridge rectifier
• leads
• small foam pad taped down under solenoid

Method:

Instructor Use Only.

Warning: Ensure that no one looks down the solenoid once the circuit is powered up, in case the solenoid fires unexpectedly. The power should be turned off when done.

With the equipment connected as shown, press the button. If the magnet is pointed the right way, it will shoot into the air. A short pulse is sent into the solenoid such that the magnet is pulled into the solenoid to the half-way position, at which point the solenoid turns off.