Question 251Electricity & Electronics - Assistant Engineer

The correct answer is A) 15 volts. In a tapped step-down transformer, the turns ratio determines the output voltage. With a turns ratio of 4:1, the output voltage will be one-fourth of the input voltage. Since the input voltage is 120 volts, the output voltage across terminals X1 and X2 will be 120 volts / 4 = 15 volts. The other options are incorrect because B) 30 volts is double the actual output, C) 480 volts is four times the input voltage, and D) 960 volts is eight times the input voltage, all of which do not match the 4:1 turns ratio of the transformer.