Single-Phase Rheostat, Classroom Grade Lab Supplies_Classroom large enough for whole-class visibility

large enough for whole-class visibility when tracing magnetic field lines around bar magnets

3 glass Griffin-form beaker shot glasses hold 3

preserving the field between teaching sessions

Eleven-ohm 5A air-cooled rheostat with constantan winding on a 300x44mm vitreous-enameled steel tube and a slide-bar carriage carrying a phosphor-bronze contact

Single-Phase Rheostat, Classroom Grade Lab Supplies_Classroom large enough for whole-class visibilityHundred ohm 1. 75A single phase rheostat with cover protected constantan winding on a 200x56mm tube and 4mm safety socket terminals, with plus or minus 10% nominal value tolerance.