A generator produces 60 A of current at 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find the number of turns in the secondary if the primary has 200 turns.

Faraday's law: A changing magnetic field induces an emf.

Lenz's law:  current produced by an induced emf moves in a direction so that its magnetic field opposes the original change in flux.

The three ways that an emf can be induced in a loop of wire.
1. by changing the magnetic field
2. by changing the area of the loop in the field
3. by changing the loop's orientation with respect to the field