Question

If in an alternating current circuit, impedance is 26 ohm, capacitive reactance is 24 ohm, what is the resistance?

(a) 25 ohm

(b) 10 ohm

(c) 12 ohm

(d) 23 ohm

The question was asked in semester exam.

The above asked question is from Resistance and Capacitance in Series in section Single Phase Series Circuits of Basic Electrical Engineering

Answer 1

Right answer is (b) 10 ohm

The best I can explain: Z=26Ω, XC=24Ω

Z^2=R^2+XC^2  Substituting the values we get,

26^2 = R^2 + 24^2

676 = R^2 + 576

R^2 = 100

R=10 Ω.