Question

What is the formula for the temperature rise of the transformers?

(a) temperature rise = total loss * specific heat dissipation * surface temperature

(b) temperature rise = total loss / (specific heat dissipation * surface temperature)

(c) temperature rise = total loss / specific heat dissipation / surface temperature

(d) temperature rise = total loss * specific heat dissipation / surface temperature

I had been asked this question in homework.

My doubt is from Temperature Rise in Transformers in chapter Design of Transformers of Design of Electrical Machines

Answer 1

The correct choice is (b) temperature rise = total loss / (specific heat dissipation * surface temperature)

To explain I would say: Firstly the surface temperature is calculated along with the specific heat dissipation which is nothing but 12.5. Then the losses are calculated and substituted in the above formula.