If the frequency of input voltage of a transformer is increased

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If the frequency of input voltage of a transformer is increased keeping the magnitude of voltage unchanged, then

1. both hysteresis loss and eddy current loss in the core will increase
2. hysteresis loss will increase but eddy current loss will decrease
3. hysteresis loss will decrease but eddy current will increase
4. hysteresis loss will decrease but eddy current will remain unchanged.

Correct Option: D

P_h = k_n ƒ B_m^1.6 = k_h ƒ B_m B_m^0.6
P_e = k e ƒ² B_m²
Also, V= 4.44 ƒ B_m A₁ N
If frequency is increased, while V remains constant, B_m will decrease; however, ƒ B_m remains constant. Thus, eddy current loss P_e remains unchanged.

P_h1	=		B_m1		^0.6	=		ƒ₂		^0.6
P_h2			B_m2					ƒ₁

Hence, as frequency increases. P_h decreases.