Q. 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
Explanation
[Solution] Input power = output power = 44 W; $I_p = 44/220 = 0.2$ A. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.