Amateur Extra › E5 Electrical Principles › E5C11
E5C11
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?
Pick an answer to check it.
Answer: B. Point 3
XL = 2 pi f L = 2 x 3.1416 x 3.505e6 x 18e-6 = about 396 ohms. The impedance is 300 + j396, which is 300 to the right and about 400 up: Point 3.
Tip: Inductive points plot above the axis.