Phasor Addition (V_R, V_L, V_C) — Practice Quiz

Question 1

In a series LCR phasor diagram, V_R = 40 V, V_L = 30 V, V_C = 60 V. Source voltage:

Accepted Answer

50 V

Answer

70 V

Answer

130 V

Answer

100 V

Question 2

On a phasor diagram with current along +x, V_L is drawn:

Accepted Answer

Along +y (90° CCW)

Answer

Along +x

Answer

Along −y

Answer

Along −x

Question 3

Phase angle φ is positive when:

Accepted Answer

V_L > V_C (inductive)

Answer

V_C > V_L (capacitive)

Answer

V_R = 0

Answer

Resistance is largest

Question 4

Two voltages V₁ = 10 sin(ωt) V and V₂ = 10 sin(ωt + 90°) V add to:

Accepted Answer

14.14 sin(ωt + 45°) V

Answer

20 sin(ωt + 45°) V

Answer

10 sin(ωt) V

Answer

10 sin(ωt + 90°) V

Question 5

Phasor analysis works because:

Accepted Answer

All sinusoids of the same ω can be represented as rotating vectors

Answer

Capacitors don't exist

Answer

Phase doesn't matter

Answer

Impedance is real