In a three-phase system with line-to-line voltage 480 V and line current 10 A, the apparent power S equals?

In a three-phase system with line-to-line voltage 480 V and line current 10 A, the apparent power S equals?

• A. 4.16 kVA
• B. 8.31 kVA
• C. 9.60 kVA
• D. 12.00 kVA

Answer: (B)

In a balanced three‑phase system, apparent power is S = √3 × V_LL × I_L. With a line-to-line voltage of 480 V and a line current of 10 A, S = √3 × 480 × 10 ≈ 1.732 × 4800 = 8313.6 VA, or about 8.31 kVA. This value represents the magnitude of the complex power (P + jQ); knowing the power factor would let you split it into real and reactive components (P = S cos φ, Q = S sin φ). For a balanced system, this is the correct way to compute apparent power from line quantities.

In a balanced three‑phase system, apparent power is S = √3 × V_LL × I_L. With a line-to-line voltage of 480 V and a line current of 10 A, S = √3 × 480 × 10 ≈ 1.732 × 4800 = 8313.6 VA, or about 8.31 kVA. This value represents the magnitude of the complex power (P + jQ); knowing the power factor would let you split it into real and reactive components (P = S cos φ, Q = S sin φ). For a balanced system, this is the correct way to compute apparent power from line quantities.