Multiple choice general knowledge

Large transformers, when used for some time, become very hot and are cooled by circulating oil. The heating of the transformer is due to

  1. the heating effect of current alone

  2. hysteresis loss alone

  3. both the heating effect of current and hysteresis loss

  4. intense sunlight at noon
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Transformers heat up due to both resistive heating from current flow (I²R losses) and hysteresis losses from repeated magnetization and demagnetization of the core. Eddy currents in the core also contribute. Oil circulation dissipates this heat. Option C correctly identifies both major heating sources, while the sun is irrelevant for internal heating.

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