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A step down transformer connected to an ac mains supply of 220 V is made to operate at 11 V, 44 W lamp. Ignoring power losses in the transformer, what is the current in the primary circuit?
A
0.4 A
B
2 A
C
4 A
D
0.2 A
Detailed Solution
For an ideal transformer, input power = output power: $220 \times i_p = 44$
$i_p = \frac{44}{220} = 0.2$ A