## Conceptual Physics (12th Edition)

a. Use the transformer relationship. $$\frac{primary \; voltage}{\# \; of \; primary \; turns} = \frac{secondary \; voltage}{\# \; of \; secondary \; turns}$$ $$\frac{12 V}{50 turns} = \frac{secondary \; voltage }{250 turns}$$ The secondary voltage is 60 volts. b. Use Ohm’s law. $$Current = \frac{voltage}{resistance}$$ $$I = \frac{60 V}{10 \Omega} = 6 A$$ c. Power is the product of current, I, and voltage, V. Calculate it for the secondary. Electric power is the same in both the primary and secondary coils of an ideal transformer. $$Electric \; power = (current) \times (voltage)$$ $$P = (6 A)(60 V) = 360 W$$