Transformer equation

Definition

The transformer equation relates the primary and secondary voltages of a transformer to the number of turns in their respective coils. It is given by $\frac{V_s}{V_p} = \frac{N_s}{N_p}$, where $V$ represents voltage and $N$ represents the number of turns.

5 Must Know Facts For Your Next Test

1. The transformer equation is derived from Faraday's Law of Electromagnetic Induction.
2. It assumes an ideal transformer with no energy losses.
3. The ratio of the voltages is equal to the ratio of the number of turns in the primary and secondary coils.
4. For step-up transformers, the secondary voltage is greater than the primary voltage ($N_s > N_p$).
5. For step-down transformers, the secondary voltage is less than the primary voltage ($N_s < N_p$).

Review Questions

• What does the transformer equation relate?
• How can you determine if a transformer is step-up or step-down using its coil turns?
• What assumption about energy losses does the transformer equation make?

Related terms

Faraday's Law of Electromagnetic Induction: States that a change in magnetic flux through a circuit induces an electromotive force (EMF) in the circuit.

Step-up Transformer: A transformer that increases voltage from primary to secondary coil.

Step-down Transformer: A transformer that decreases voltage from primary to secondary coil.