Question

A transformer has hysteresis and eddy current loss of 700 W and 500 W, respectively when connected to 1000 V,50−Hz supply. If the applied voltage is raised to 2000 V and frequency to 75 Hz, find the new core losses.

Answer 1

The new core losses of the transformer, when voltage is increased to 2000 V and frequency to 75 Hz, are calculated based on proportions to voltage and frequency, resulting in a total of 3862.5 W combining both hysteresis and eddy current losses.

Step-by-step explanation:

The subject of this question is related to Physics, specifically the area concerning transformers and core losses, which include hysteresis and eddy current losses. When the applied voltage of a transformer is increased from 1000 V to 2000 V, and the frequency from 50 Hz to 75 Hz, the new core losses need to be calculated considering the proportionality of these losses to the voltage and frequency. Since eddy current losses are proportional to the square of voltage and frequency (V2f2), and hysteresis losses are proportional to frequency (f), the changes would affect each differently.

• The original hysteresis loss at 700 W would increase by a factor of ½ (the frequency increase), resulting in new hysteresis losses of 1050 W.
• The eddy current loss, originally 500 W, will increase by a factor of 4 (the voltage increase) and further by a factor of ∙5/4 (the frequency increase), resulting in new eddy current losses of 2812.5 W.

Therefore, the total new core losses would be the sum of the new hysteresis and eddy current losses, which would be 1050 W + 2812.5 W = 3862.5 W.