🔍 Key Concepts

• Impedance (Z) in AC circuits combines resistance (R), inductive reactance (XL), and capacitive reactance (XC) into one value • In a series RLC circuit, impedance is found using a Pythagorean-type relationship because voltage and current are out of phase • The expression inside the impedance formula often involves (XL - XC), not just a simple sum

💭 Think About

• Is impedance (Z) usually expressed as a simple arithmetic sum of R, XL, and XC, or as a relationship involving squares (like Pythagoras)? • In an RLC series circuit, how are the reactive parts (XL and XC) combined first—are they added, subtracted, or multiplied? • When you see Z squared in a formula, what does that suggest about how the real part (R) and the reactive part (XL - XC) are related geometrically?

✅ Before You Answer

• Check whether the correct formula for impedance in a series RLC circuit involves Z squared (Z × Z) or just Z alone • Verify that R appears as R × R (or R²) and the reactance term appears as (XL - XC) × (XL - XC) (or (XL - XC)²) in the relationship • Eliminate any choices that treat impedance as a simple linear sum without using a squared relationship between R and the net reactance