A step down transformer has primary voltage 1100V. The transformer ratio is 1 : 5. If the primary current is 10A find the secondary voltage, secondary current assuming the transformer to be an ideal transformer.

For the step-down transformer with transformer ratio 1:5; 

primary voltage ${\mathrm{V}}_{\mathrm{P}}=1100 \mathrm{V}$ and primary current ${\mathrm{I}}_{\mathrm{P}}=10 \mathrm{A}$.

Hence, secondary voltage ${\mathrm{V}}_{\mathrm{S}}=1100\times \frac{1}{5}=220 \mathrm{V}$.

Assuming zero loss in the transformer, secondary current

${\mathrm{V}}_{\mathrm{S}}{\mathrm{I}}_{\mathrm{S}}={\mathrm{V}}_{\mathrm{P}}{\mathrm{I}}_{\mathrm{P}} \Rightarrow {\mathrm{I}}_{\mathrm{S}}=\frac{{\mathrm{V}}_{\mathrm{P}}{\mathrm{I}}_{\mathrm{P}}}{{\mathrm{V}}_{\mathrm{S}}}=\frac{1100\times 10}{220}=50 \mathrm{A}$.