Question

The readings of polar type potentiometer are I = 12.4∠27.5°, V = 31.5∠38.4°. Then, reactance of the coil will be ________

(a) 2.51 Ω

(b) 2.56 Ω

(c) 2.54 Ω

(d) 2.59 Ω

The question was asked in semester exam.

This interesting question is from Advanced Problems on Measurement of Low Medium and High Resistance topic in chapter Measurement of Resistance of Electrical Measurements

Answer 1

The correct option is (c) 2.54 Ω

Explanation: Here, V = 31.5∠38.4°

I = 12.4∠27.5°

Z = \(\frac{31.5∠38.4°}{12.4∠27.5°}\) = 2.54∠10.9°

But Z = R + jX = 2.49 + j0.48

∴ Reactance X= 2.54 Ω.