Also called Demonstration Induction Coils consists of two coils wound on separate bobbins, one having many turns of fine wire & the other with few turns of heavy wire. It demonstrates that induced potentials are produced either by movement of a permanent or electromagnet or by a change of current in one coil, fitted with insulated 4 mm socket terminals & supplied with a soft iron core, outer coil is 12. 5 cm long & is of 5 cm diameter.
