Question

The circuit shown below consists of a 1kΩ resistor connected in series with a 50mH coil, a 10V rms, 10 KHz signal is applied. Find impedance Z in rectangular form.

(a) (1000+j0.05) Ω

(b) (100+j0.5) Ω

(c) (1000+j3140) Ω

(d) (100+j3140) Ω

The question was posed to me in an interview for job.

My question is taken from Series Circuits in section Complex Impedence of Network Theory

Answer 1

Correct answer is (c) (1000+j3140) Ω

To elaborate: Inductive Reactance XL = ωL = 2πfL = (6.28)(10^4)(50×10^-3) = 3140Ω. In rectangular form, total impedance Z = (1000+j3140) Ω.