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:
Options

Question

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:

Options

G1 Physics · Accepted Answer

Step 1: Transformer efficiency η=Pₛ/Pₚ=0.90, with primary input power Pₚ=3kW. Step 2: Output power Pₛ=0.9×3000=2700W; with Iₛ=6A, secondary voltage Vₛ=Pₛ/Iₛ=450V. Step 3: Primary current Iₚ=Pₚ/Vₚ=3000/200=15A. Pair (450V,15A) is option B. Final answer: (B) 450 V, 15A.