PURPOSE: To visualize the magnetic field around a solenoid.
DESCRIPTION: Solenoids of three and seven turns respectively are wound through a plastic sheet. The magnetic field around either solenoid can be visualized by sprinkling iron filings in the area around where the solenoid passes through a plasti c sheet which is positioned on an overhead projector. Alternatively, small compasses can be arranged within and around the solenoids.
SUGGESTIONS: This is a portable version; a better choice in Physics classrooms is J5-16: MAGNETIC FIELD AROUND WIRE, LOOP, SOLENOID.
EQUIPMENT: EME magnetic field apparatus with battery electric current source on overhead projector.
SETUP TIME: None.