A current of $5 \mathrm{~A}$ is flowing at $220 \mathrm{~V}$ in the primary coil of transformer. If the…
A current of $5 \mathrm{~A}$ is flowing at $220 \mathrm{~V}$ in the primary coil of transformer. If the voltage produced in the secondary coil is $2200 \mathrm{~V}$ and $50 \%$ of power is lost, then the current in secondary will be
2.5 A
0.5 A
0.25 A
5 A
Solution
Let $I$ be the current flowing through secondary coil.
Current on primary (input) coil $i=5 \mathrm{~A}$
Voltage in primary coil $V=220 \mathrm{~V}$
Voltage in secondary coil $V^{\prime}=2200 \mathrm{~V}$
Considering only $50 \%$ power is transmitted:
$\begin{aligned}
& 0.5(\mathrm{Vi})=V^{\prime} I \\
& \therefore 0.5 \times 220 \times 5=2200 \times I \\
& \Rightarrow I=0.25 \mathrm{~A}
\end{aligned}$