The Ideal Transformer Equation Flashcards

All 4 cards in this deck

What is the equation linking the potential differences and currents of a 100% efficient transformer?

$V_p \times I_p = V_s \times I_s$

What assumption is made when using $V_p \times I_p = V_s \times I_s$?

That the transformer is 100% efficient — the power output equals the power input.

What are the steps to find the secondary current of a 100% efficient transformer?

e.g. $V_p = 200$ V, $I_p = 3$ A, $V_s = 20$ V

1. Write $V_p \times I_p = V_s \times I_s$: $200 \times 3 = 20 \times I_s$
2. Rearrange: $I_s = \dfrac{600}{20}$
3. $I_s = 30$ A

True or false? A step-up transformer increases both the potential difference and the current.

False. As the p.d. is stepped up the current is stepped down, since the power output cannot exceed the power input.