If an inductor has a reactance of 40 ohms and is connected in series with a resistor of 60 ohms, what is the total impedance?

To find the total impedance in a circuit where an inductor and a resistor are connected in series, you need to use the formula for impedance in this context. The total impedance (Z) can be calculated by combining the resistance (R) and the inductive reactance (X_L) using the following formula:

Z = √(R² + X_L²)

Here, the reactance of the inductor is given as 40 ohms, and the resistance of the resistor is 60 ohms. Plugging these values into the formula gives:

Z = √(60² + 40²)

Z = √(3600 + 1600)

Z = √5200

Z = 72.11 ohms

When rounded appropriately or approximated realistically in practical scenarios, this value can be considered close to 70 ohms. However, the concept helps clarify that the total impedance is more than just the sum of the two values due to the phase differences in an AC circuit.

The correct choice reflects an understanding of how to combine resistive and reactive elements in series, which leads to the total impedance being greater than the individual components due to their different characteristics in the circuit.