A three-phase alternator operates at 450...

Question 1 / 270705eccefa3bacbc34ba4d480e2

Question 1 of 270705eccefa3bacbc34ba4d480e2

A three-phase alternator operates at 450 volts with a 0.8 power factor. If the ammeter indicates 250 amperes, what should be the kW meter reading?

Back

Question 1 of 27070

A three-phase alternator operates at 450 volts with a 0.8 power factor. If the ammeter indicates 250 amperes, what should be the kW meter reading?

🔍 Key Concepts

• Three-phase power formula for real power (kW) in a balanced system • Relationship between line voltage, line current, and power factor • How to convert from kVA to kW using power factor

💭 Think About

• Start by recalling the standard formula for three-phase real power using line voltage, line current, and power factor. Which constant (like √3) belongs in that formula? • Calculate the apparent power (in kVA) first using voltage and current. Then ask: how does power factor change kVA into kW? • Once you have the kW value from your formula, compare it to the choices. Does it match one of them closely without extra rounding steps?

✅ Before You Answer

• Be sure you are using line values (450 V and 250 A) correctly in the three‑phase formula, not single‑phase formulas • Confirm you are multiplying by power factor (0.8) at the correct step—after you find apparent power, not before • Double-check your calculator work for the square root of 3 (≈1.732) and make sure units end up in kW rather than W or kVA

Question 1 of 27070

A three-phase alternator operates at 450 volts with a 0.8 power factor. If the ammeter indicates 250 amperes, what should be the kW meter reading?

90.00 kW

127.27 kW

155.70 kW

194.85 kW