Question

A step down transformer connected to an ac mains supply of 220 V is made to operate at 11V, 44 W lamp. Ignoring power losses in the transformer, what is the current in the primary circuit?

(1) 0.2 A 

(2) 0.4 A 

(3) 2A 

(4) 4A

Answer 1

Option : (1) 0.2 A 

220 × i_p = 44

⇒ i_p = \(\frac{44}{220}\) = \(\frac{1}{5}\) = 0.2A