Atransformer changes the 10,000 v power line to 120 v. if the primary coil contains 750 turns, how many turns are on the secondary?

For a transformer, the ratio between the number of turns of primary and secondary coil is the same as the ratio between the voltages on the two coils:

Where and are the number of turns in the primary and secondary coils, while and are the voltages on the two coils.

Using the data of the problem: , and , we can find , the number of turns of the secondary coil: