In this animated activity, learners see that changing the resistance value of the load in the secondary of a transformer causes current to vary in the primary.

Learners view the waveforms and voltages of an Edison Three-Wire System and read a description of the polarities across the secondary of the center-tap transformer. This transformer supplies power to residential homes.

Students solve practice problems on voltage, current, and impedance matching. Examples precede the problems.

Learners read an analogy comparing an electrical transformer to mechanical gears.

Learners take a close look at the Edison Wire System and observe how the current values through the two lines and the neutral of the system change as the loads vary.

Students read descriptions of the voltage, current, and turns ratios of the primary and secondary coils for a transformer in this interactive lesson.

Students read an introduction to transformers that includes schematic symbols, turns ratios, mutual inductance, and the coefficient of coupling.