Physics Voltage Transformer

Question

An ideal transformer has 50 turns in its primary and 400 turns in its secondary. 14-VV ac is connected to the primary. What is the voltage available at the secondary? What is the current in a 6 Ω device connected to the secondary? What is the power supplied to the primary? Not sure how to set up this problem.

Answer 1

Using the basic equation:

(where V_P is the voltage on the primary, V_S is the voltage on the secondary, N_P is the number of turns on the primary and N_S is the number of turns on the secondary)

Solve for V_S:

V_S = (V_P)(N_S)/(N_P)

(14)(400)/(50) = 112 V on the secondary.

If a 6 Ω device is connected, use Ohm's Law to find the current (I): V = IR therefore I = V/R = 112/6 = 18.7 A