Torques on Coils Concept

Demonstrations in Torques on Coils

Leeds and Northrup ballistic galvanometer: black metal housing with front window showing internal mirror and coil assembly, manufacturer label with specifications, suspension tube extending from top, mounted on three-legged cast iron base with brass leveling screws
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Leeds and Northrup Ballistic Galvanometer

Illustrates the moving-coil galvanometer principle: current through a suspended coil in a magnetic field produces torque, deflecting a mirror whose rotation is read optically. A historical example of precision analog …
Welch galvanometer with black metal casing, semicircular scale marked -5 to +5, open window showing internal coil mechanism, schematic diagram on face, and binding posts on front panel
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Welch Lecture Table Meter

Demonstrates the operating principle of a d'Arsonval (moving-coil) galvanometer. The open construction allows students to see the coil, magnet, and suspension while the schematic on the dial face illustrates the …
Wire coil suspended between poles of a horseshoe magnet on a wooden base, connected via red wires to a Xantrex DC power supply reading 3.17 V
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Current Loop in Magnetic Field

A current-carrying coil suspended in a horseshoe magnet's field rotates to align with the field, demonstrating the torque on a magnetic dipole. Students observe the motor principle: magnetic forces on …
Two copper coils suspended by thin red wires from a support rod on a ring stand, connected via binding posts and red/black leads to a DC power supply reading 34.0V
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Suspended Coils

Demonstrates that parallel currents attract and antiparallel currents repel, providing a direct observation of Ampère's force law. The freely suspended coils swing visibly when energized, making the magnetic interaction between …
CENCO motor-generator model running as a motor: armature is a blur spinning between red (left) and green (right) field coils, mounted on white metal frame with blue base. Xantrex power supply at right reads 6.0V, 00.8A. Four binding posts with red wires visible on top crossbar.

Motor and Generator Demonstration Model

A transparent CENCO motor/generator model demonstrates three configurations: series motor, shunt-wound motor, and hand-cranked generator. Students observe torque on a current-carrying coil, the effect of reversing polarity in different winding …