Red Seal Electrician Practice
Electrical mathQuestion 154 of 1506

A vector is 50 V @ 210°. What is its rectangular form, rounded?

  1. 43.3, j25
  2. −25, −j43.3
  3. −43.3, −j25
  4. −43.3, j25
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Correct answer: −43.3, −j25

The reference angle is 210° − 180° = 30°. In quadrant 3 both X and Y are negative: X = −50 cos 30° = −43.3 and Y = −50 sin 30° = −25.

Source: Trigonometry and Single Phase AC Generation for Electricians (Flinn), 2.2: Quadrants

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Questions last reviewed: 18 October 2026