A step-down transformer has a turns ratio of 1:10, and itsprimary is connected across the terminals of a standard 120-V wallsocket. A 470-W resistor is connected across the secondary of thistransformer. What power P is dissipated in the resistor? I am apparently using an incorrect formula, please help. A step-down transformer has a turns ratio of 1:10, and itsprimary is connected across the terminals of a standard 120-V wallsocket. A 470-W resistor is connected across the secondary of thistransformer. What power P is dissipated in the resistor? I am apparently using an incorrect formula, please help.
Explanation / Answer
Ratio of truns N / N ' = 1 / 10 Primary voltage V = 120 V Secondary voltage V ' = ( N ' / N ) V = 1200 Volt Resistance R = 470 ohm So, power dissipated in the resistor P = V ' ^ 2 /R =3063.82 W