A transformer has 100 turns on the primary and 50 on the secondary. With 240 volts applied to the primary, what is the secondary voltage?

Correct answer to question 40 (Electronics Information): 120 volts

Method

Output voltage follows the turns ratio, so halving the turns halves the voltage: 240 x 50 / 100 = 120 volts. Inverting the ratio gives 480, which would be a step-up transformer.