Physics - EMI/AC Question with Solution | TestHub

Given: Output power,$P=100 \mathrm{W}$

The voltage across the primary coil,$V_p=220 \mathrm{V}$

Current in the primary coil,$I_p=0.5 \mathrm{A}$

The efficiency of a transformer,$\text{η}=\frac{\text{output power}}{\text{input power}}\times 100$

$=\frac{\mathit{\text{P}}}{{\mathit{\text{V}}}_{\text{p}}{\text{I}}_{\text{p}}}\times 100=\frac{100}{220\times 0.5}\times 100\approx 91\text{\%}$