12-13 Transformers Recap

Front

What is the main use of a transformer in an electrical distribution system?

Back

It allows for voltage conversion with minimal power loss.

Front

In a step-down transformer, what happens to voltage and current?

Back

Voltage decreases, Current increases.

Front

What is the turn ratio in a step-down transformer?

Back

Higher on the primary than the secondary.

Front

What does a transformer not change?

Back

Frequency.

Front

What is the formula for calculating impedance in a circuit with resistance and reactance?

Back

Z = √(R² + (X_L - X_C)²) where R is resistance, X_L is inductive reactance, and X_C is capacitive reactance.

Front

If a transformer has a primary voltage of 240V and a secondary voltage of 120V, what type of transformer is it?

Back

Step-down transformer.

Front

What is the relationship between primary and secondary voltage in a transformer?

Back

V_p / V_s = N_p / N_s, where V is voltage and N is the number of turns.

Front

What is the efficiency of an ideal transformer?

Back

100%, as it does not lose power.

Front

What happens to power in a transformer?

Back

Power is conserved; P_p = P_s (Power in primary = Power in secondary).

Front

What is the effect of increasing the number of turns in the primary coil of a transformer?

Back

It increases the primary voltage.