Question

A transformer consisting of $300$ turns in the primary and $150$ turns in the secondary gives output power of $2.2kW$.If the current in the secondary coil is $10A$, then the input voltage and current in the primary coil are :

• A. $220V$ and $10A$
• B. $440V$ and $5A$
• C. $440V$ and $20A$
• D. $220V$ and $20A$

Answer 1

The correct option is B $440V$ and $5A$

Given $N_P=300,N_s=150,P_0=2200W$
$I_s=10A$
$P_0=V_0{I}_0\Rightarrow 2200=V_0\times 10\Rightarrow V_0=220V$
$\because \frac{V_i}{V_0}=\frac{N_p}{N_s}\Rightarrow V_i=2\times 220=440V$
Also $P_0=V_i{I}_i$
$\Rightarrow I_i=\frac{2200}{440}=5A$