Question

A step-up transformer operates on a $230V$ line and supplies a load of $2$ ampere. The ratio of the primary and secondary windings is $1:25.$ The current in the primary is

• A. $15A$
• B. $50A$
• C. $25A$
• D. $12.5A$

Answer 1

Answer: (B)

$\frac{E_{P}}{E_{s}}=\frac{N_{P}}{N_{s}}=\frac{1}{25};E_{s}=5750V$
$\frac{E_{P}}{E_{s}}=\frac{N_{P}}{N_{s}}=\frac{1}{25};E_{s}=5750V$
$I_{P}=\frac{P_{P}}{V_{P}}=\frac{P_{S}}{V_{P}}=\frac{2 \times 5750}{230}=50A$