A transformer has 400 W as iron loss at full load. What is the iron loss at half load. a. 50 W b. 100 W c. 200 W d. 400 W

A transformer has 400 W as iron loss at full load. What is the iron loss at half load. a. 50 W b. 100 W c. 200 W d. 400 W Correct Answer d

• A transformer has mainly two types of losses, these are, iron losses and copper losses
• Iron loss, which is also referred to as core loss, consists of hysteresis loss and eddy current loss
• These two losses are constant when the transformer is charged
• That means core losses does not depend upon the condition of a secondary load of the transformer; In all loading condition, these are constant
• Hence If the full-load iron loss of a transformer is 400 W, the iron loss at half-load is 400 W
• But the copper loss which is also referred as I2R loss entirely depends upon load current I
• Distribution transformers have core losses less than full load copper losses