Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?

Erklärung
The inductor's reactance at 3.505 MHz is about 396 Ω and is positive because it is inductive, giving an impedance near 300 + j396 ohms. That places the point 300 to the right and 400 above the axis on Figure E5-1, which is Point 3; the other candidates lie below the axis or on it.