For ordinary magnets, iron bars, strips etc. Consists of a 250 mm long solenoid wound with insulated copper wire and mounted on a base, with switch and 4mm terminals. Operating voltage is 12 V A.C. or D.C. At 6A max.

Iron, U core, circular section, with flat ends, has one bobbin in each limb wound with enameled copper wire, with armature.

This Relay Demonstration Unit allows the investigation and study of how a relay functions in a clear and practical manner. A useful property of this Demonstration Relay Unit is that the circuit powering the coil is easily seen to be completely separate from the circuit-switched on by the relay. This is one of the reasons relays are used where a safe low-voltage circuit can be used to control a high-voltage circuit. When a current flows through the coil an electromagnetic field is produced. This field attracts the iron armature whose end makes the contact, completing the circuit and illuminating the Lamp. When the current is switched off, the contact will open again, switching the circuit off.

To demonstrate the electromagnetism. A pair of powerful magnets in U shape holder. A pair of brass rail with 4 mm socket is used for demonstration. A brass axle with two plastic discs is free to roll along the rails and complete the circuit between rails. As the axle placed on the rails near the poles of magnets and power supplied to the rails, the axle repelled and rolls away from the center of magnetic field along the rails.

To demonstrate that when a current is passed through a conductor in a magnetic field, it is subjected to attraction or repulsion depending upon the direction of current in it. The apparatus consists of a plastic base 9″ x 6″ x 1″ on which two contact pillars are mounted. Each pillar is provided with an external circuit. A balanced beam is supported by the pillars on two bearings which form the fulcrum. Two screwed masses are provided in the beam system, one moving vertically for the adjustment of sensitivity and the other moving horizontally for the adjustment of the equilibrium position, when no current is flowing. Scale is marked 0-80 x 1 mm and rider is of 1 gm. Includes instruction manual.

Helmholtz Coils are a special arrangement of coils that are placed in such a way as to generate a very uniform magnetic field between them when a current is applied. The strength of the magnetic field is proportional to the number of turns in the coils and the current applied to them. The Supertek Helmholtz Coils setup consists of two field coils mounted on a track to provide a uniform magnetic field between the coils. The proper separation for Helmholtz coils is marked on the track. A pair of precision coils and 400 turns of wire are wound on heat-resistant former of about 150 mm diameter.