A wattmeter is marked 15 A/30 A, 300 V/600 V and its scale is marked up to 4500 watts. When the meter is connected to 30 A, 600 V, the point indicated 2000 watts
A wattmeter is marked 15 A/30 A, 300 V/600 V and its scale is marked up to 4500 watts. When the meter is connected to 30 A, 600 V, the point indicated 2000 watts. The actual power of the circuit is
Right Answer is:
8000 watts
SOLUTION
Power consumed by wattmeter = CT ratio × PT ratio × VIcosΦ……..1
In the above question
Power consumed by wattmeter = 2000 watts
CT ratio = 15 / 30
PT ratio = 300 / 600
VI = 600 × 30
Putting all the value in equation number 1 we get
2000=(15/30) × (300/600) × 600 × 30 × cosΦ
CosΦ = 0.4444
Power = VI cosΦ = 600 x 30 x 0.4444
Power = 7999.2 ≅ 8000 watts