🔍 Key Concepts

• Transformer turns ratio and how it affects voltage and current between primary and secondary • How a load resistance/impedance on the secondary is reflected back to the primary (reflected impedance) • Using Ohm’s Law (V = I × R) once you know the correct voltage and resistance in the secondary circuit

💭 Think About

• First, use the given turns ratio (1 to 10) and the 110 VAC primary voltage to figure out the secondary voltage of this step-up transformer. What does a 1:10 step-up mean numerically? • With that secondary voltage and the 440-ohm load, what is the secondary current using Ohm’s Law? Is this a large or small value compared to the answer choices? • Next, think about how current changes from secondary back to primary in an ideal transformer. Does the primary current become 10 times larger or 10 times smaller than the secondary current, given this is a step-up transformer?

✅ Before You Answer

• Be sure you apply the turns ratio correctly: primary-to-secondary versus secondary-to-primary; don’t invert it by mistake • Double-check your Ohm’s Law calculation for the current through a 440-ohm load at the calculated secondary voltage • Before picking an answer, compare your calculated primary current to the choices and confirm your units are amps, not milliamps or some other unit