🔍 Key Concepts

• Transformer basics: relationship between primary and secondary windings • How load on the secondary affects current flow • The idea that the primary "reacts" to keep power in = power out (minus losses)

💭 Think About

• If the secondary load increases, what happens to the secondary current? Then, how must the primary side change to supply that extra power? • Think about which side (voltage or current, primary or secondary) is mostly held constant in normal operation, and which variable is allowed to change. • In a typical power transformer connected to a stable source, does the supply voltage tend to vary a lot, or does the current drawn tend to vary more with load?

✅ Before You Answer

• Assume the primary voltage is supplied by a stable power source (like a ship’s bus). What does that mean about how much it can change? • Recall the approximate relationship: Power in ≈ Power out. If secondary power goes up because of more load, which primary quantity must increase to match that power? • Eliminate any choice that suggests the primary is doing the opposite of what’s needed to deliver more power to the load.