(i)Out of the two arrangements given below, for winding of primary and secondary coils in a transformer, which arrangement do you think will have higher efficiency and why?

(ii) Show that, in ideal transformer, when the voltage is stepped up by a certain factor, the current gets stepped down by the same factor.
(iii) State any two causes of energy loss in transformer.

Solution

(i) Arrangement (a)will have higher efficiency because leakage flux in this arrangement is minimum.

(ii) For an ideal transformer,

\frac{ε_{s}}{ε_{p}} = \frac{I_{p}}{I_{s}} = \frac{N_{s}}{N_{p}},

∴

ε_{s} = (\frac{N_{s}}{N_{p}}) ε_{p}

and

I_{s} = (\frac{N_{p}}{N_{s}}) I_{p}

\Rightarrow

Voltage is stepped by the factor

(\frac{N_{s}}{N_{p}})

and current is by the factor of

(\frac{N_{p}}{N_{s}})

or stepped down by the same factor i.e.,

(\frac{N_{s}}{N_{p}}) .

(iii) Two causes of energy loss in transformer are
1. Leakage of flux
2. Eddy current loss.

For Daily Free Study Material Join wiredfaculty