A power transmission line feeds input power at 2300 V a step down transformer with its primary windings having 4000 turns. The output power is delivered at 230 V by the transformer. If the current in the primary of the transformer is 5A and its efficiency is `90%`, the output current would be :

Options

A. 45 A
B. 50 A
C. 20 A
D. 25 A

Answer

A

Explanation

(a ) Efficiency `eta=0.9=(P_("output"))/(P_("input"))=(V_(S)I_(S))/(V_(P)I_(P))`
`I_(S)=(0.9xx2300xx5)/(230)` =45 A
Hence option (A) is correct .