EIT Electrical Circuits 3

Question 1

What is the resonant frequency of an LC circuit with L = 0.1H and C = 100μF?

Accepted Answer

15.9 Hz

Answer

1.59 Hz

Answer

159 Hz

Answer

1590 Hz

Question 2

In a three-phase system, what is the phase difference between each phase voltage?

Accepted Answer

120°

Answer

90°

Answer

180°

Answer

60°

Question 3

What does a phasor diagram represent?

Accepted Answer

Magnitude and phase of sinusoidal quantities

Answer

Time-domain waveforms

Answer

Frequency response

Answer

DC transient response

Question 4

The maximum power transfer theorem states maximum power is delivered when:

Accepted Answer

Load impedance = supply impedance conjugate

Answer

Load resistance = 0

Answer

Load resistance → ∞

Answer

Load reactance is maximized

Question 5

What is the time constant τ of an RC series circuit?

Accepted Answer

RC

Answer

R/C

Answer

√(RC)

Answer

1/(RC)

Question 6

In a Y-connected three-phase system, the line voltage is related to the phase voltage by:

Accepted Answer

V_line = √3 × V_phase

Answer

V_line = V_phase

Answer

V_line = 3 × V_phase

Answer

V_line = V_phase / √3