Question

In the circuit given below, the phase angle of the current I with respect to the voltage V1 is __________

(a) 0°

(b) +45°

(c) -45°

(d) -90°

The question was asked in an interview.

I want to ask this question from Advanced Problems Involving Complex Circuit Diagram in division Network Theory and Complex Circuit Diagram of Network Theory

Answer 1

Right answer is (d) -90°

For explanation: Net voltage applied to the circuit is 200∠0° V

I1 = \(\frac{200∠0°}{10.0}\)

= 20∠0° = 20

I2 = \(\frac{200∠0°}{10∠90°}\)

= 20∠-90° = -j20

I = I1 + I2 = 20(1-j) = 20\(\sqrt{2}\)∠45°

Voltage V1 = 100(1+j)

= 100\(\sqrt{2}\)∠45°

∴ Required phase angle = -45° – 45° = -90°.