A transformer consisting of 300 turns in the primary and 150 turns in the secondary gives output power
A transformer consisting of 300 turns in the primary and 150 turns in the secondary gives output power of $2.2 \mathrm{~kW}$. If the current in the secondary coil is $10 \mathrm{~A}$, then the input voltage and current in the primary coil are :
Correct Option: , 3
(3) Power output $\left(\mathrm{V}_{2} \mathrm{I}_{2}\right)=2.2 \mathrm{~kW}$
$\therefore \mathrm{V}_{2}=\frac{2.2 \mathrm{~kW}}{(10 \mathrm{~A})}=220 \mathrm{volts}$
$\therefore$ Input voltage for step-down transformer
$\frac{\mathrm{V}_{1}}{\mathrm{~V}_{2}}=\frac{\mathrm{N}_{1}}{\mathrm{~N}_{2}}=2$
$\mathrm{V}_{\text {input }}=2 \times \mathrm{V}_{\text {output }}=2 \times 220$
$=440 \mathrm{~V}$
Also $\frac{\mathrm{I}_{1}}{\mathrm{I}_{2}}=\frac{\mathrm{N}_{2}}{\mathrm{~N}_{1}}$
$\therefore \quad \mathrm{I}_{1}=\frac{1}{2} \times 10=5 \mathrm{~A}$