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Electrical mathQuestion 158 of 1506

A 30 V vector at 0° is added to a 40 V vector at 90°. What is the resultant?

  1. 70 V @ 45°
  2. 50 V @ 53.1°
  3. 50 V @ 36.9°
  4. 10 V @ 90°
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Correct answer: 50 V @ 53.1°

The sum in rectangular form is 30, j40. The magnitude is √(900 + 1,600) = 50 V and the angle is arctan(40 ÷ 30) = 53.1°.

Source: Trigonometry and Single Phase AC Generation for Electricians (Flinn), 2.4: Vector Addition

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Questions last reviewed: 18 October 2026