The core loss of a single phase, 230/115 V, 50Hz power transformer

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The core loss of a single phase, 230/115 V, 50Hz power transformer is measured from 230 V side by feeding t he pr imar y (230 V side) fr om a variable voltage variable frequency source while keeping the secondary open circuited. The core loss is measured to be 1050 W for 230 V, 50 Hz input. The core loss is again measured to be 500 W for 138 V, 30 Hz input. The hysteresis and eddy current losses of the transformer for 230 V, 50Hz input are respectively.

1. 508 W and 542 W
2. 468 W and 582 W
3. 498 W and 552 W
4. 488 W and 562 W

Correct Option: A

1 - φ	230	, 50 Hz
	115 V

Core loss = 1050 W at 230V, 50Hz
Core loss = 500W at 138V, 30 Hz

In both cases	V	ratio is constant
	f

Hence,

At 50 Hz ⇒ 1050 = A (50) + B(50)²
At 30 Hz ⇒ 500 = A (30) + B(30)²
A = 10.167
B = 0.217
∴ W_n at 50Hz = (10.167) × 50 = 508 W
W_c at 50 Hz = (0.217) × (50)² = 542 W