In a three phase four wire unbalanced system, the current in the neutral wire is 18 A. The magnitude of zero sequence current is
- A. 18 A
- B. 6 A
- C. 9 A
- D. 3 A
Answer: B. 6 A
Explanation: In a 3-phase 4-wire system, neutral current In = 3·I0. Given In = 18 A, the zero sequence current is I0 = In / 3 = 18 / 3 = 6 A.