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SarkariResultOutAdditional Assistant Engineer (Electrical) · 2026

Previous Year Question

What happens when the phase sequence of a 3-phase load is reversed?
  1. Phase powers are changed.
  2. Phase currents change in phase angle but not in magnitude.
  3. Phase currents are changed in magnitude.
  4. The total power consumed is changed.

Correct answer: B

Explanation

For a balanced symmetrical load, reversing phase sequence changes the order/phase relation of the three phase quantities but not their magnitudes. Consequently the phase-current angles reverse sequence while magnitudes and total real power remain unchanged.

Step-by-step solution

Effect of Reversing Phase Sequence explanatory diagram

Correct Answer

B — Phase currents change in phase angle but not in magnitude.

Explanation

For a balanced symmetrical load, reversing phase sequence changes the order/phase relation of the three phase quantities but not their magnitudes. Consequently the phase-current angles reverse sequence while magnitudes and total real power remain unchanged.

Key Concept

Effect of Reversing Phase Sequence

Exam Point

Reverse sequence changes rotation/angle order, not balanced magnitudes.

Exam tip

Reverse sequence changes rotation/angle order, not balanced magnitudes.

Quick method

Reverse sequence changes rotation/angle order, not balanced magnitudes.