Primary & Secondary Coils – Electromagnetic Demonstration Kit
by United Scientific

This is an improved version of a classic experiment that investigates electromagnetic induction. The small diameter primary coil has 175 turns of 18 AWG insulated copper wire, and a pair of shielded sockets. The larger diameter secondary coil features 1500 turns of 26 AWG wire, and its four shielded sockets allow for 500, 1000, or 1500 turns to be selected. The unit also comes with a plated iron core, which has a molded handle.

The core and primary coil slip inside the secondary coil, and experiments can be run to demonstrate the principle of electromagnetic induction. With the ability to use either AC or DC power sources, these experiments can easily be carried out either within a laboratory setting or at a science fair. Extremely versatile, both the self-induction and mutual induction experiments can be performed with or without the iron core in place. The secondary coil can even be used as a separate solenoid.

By using an AC or DC power source, experiments can be performed to examine self-induction, mutual induction, and a magnet-and-coil experiment. The teacher’s guide includes instructions for performing all of these experiments. It is a great way to demonstrate Faraday’s Law, in which “induced voltage is proportional to the rate of change of magnetic flux in the conductor.”

The primary core has a diameter of 34mm and a length of 100mm, while the secondary coil is 52mm in diameter and 102mm in length. Including the handle, the iron core is 165mm in length, and 19mm in diameter.