Q. A transformer having efficiency of 90% is working on 200 V and 3 kW power supply. If the current in the secondary coil is 6 A, the voltage across the secondary coil and the current in the primary coil respectively are :
A) 300 V, 15 A
B) 450 V, 15 A
C) 450 V, 13.5 A
D) 600 V, 15 A
Explanation
[Solution] $I_p = \frac{3000}{200} = 15$ A; output = 0.9 × 3000 = 2700 W, so $V_s = \frac{2700}{6} = 450$ V. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.