Previous Year Question
In a balanced star connected network, what is the sum of the three phase currents at the neutral point?
Correct answer: B
Explanation
Three equal sinusoidal currents displaced by 120° have a phasor sum of zero. Therefore a perfectly balanced star load carries zero neutral current.
Formula
IR + IY + IB = 0
Step-by-step solution
Correct Answer
B — Zero
Explanation
Three equal sinusoidal currents displaced by 120° have a phasor sum of zero. Therefore a perfectly balanced star load carries zero neutral current.
Key Concept
Neutral Current
Formula
IR + IY + IB = 0
Exam Point
Balanced 3-phase star → neutral current = 0.
Exam tip
Balanced 3-phase star → neutral current = 0.
Quick method
Balanced 3-phase star → neutral current = 0.