Contents
Cal Poly Pomona
BroncoDirect Campus Map University Library

Physics Demonstrations at Cal Poly Pomona

Demo Index:
    EM-H-AD
Pira Index:
    5H 40.23
Title:
    AC VERSUS DC DEMO
Description:
    Demonstrates that the direction of current flow affects the magnetic forces.
Equipment:
    1. Yellow light bulb
    2. Strip of magnets taped together
    3. DC plug-in unit (rectifier)
    4. Variac
Procedure:
    1. Plug the light bulb unit into the wall socket and hold the magnet carefully near the top of the light bulb until the filament moves quickly back and forth.
    2. Insert the plug into the rectifier to convert the current to DC and repeat as above. Note that with DC the filament now just bends towards the magnet and stays there.