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# The $220\;v$ input is supplied to a transformer . The output circuit draws current of $2.0\;A$ at $440\;V$ If efficiency of transforms is $80\%$ te current drawn by primary circuit is

$(a)\;3.6\;A \\(b)\;2.8\;A \\ (c)\;2.5\;A \\ (d)\;5.0\;A$

$\eta$ = efficiency =$\large\frac{Output \;power}{Input\; Power}$
$\qquad= \Large\frac{V_sI_s}{V_p I_p}$
$I_p= \large\frac{440 \times 2}{\Large\frac{80}{100} \times 220}$
$\qquad= 5A$
Hence d is the correct answer.