A power transmission line feeds input power at to a step-down transformer with…

PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

A power transmission line feeds input power at

2300\,\text{V}

to a step-down transformer with primary windings having

4000

turns, giving output at

230\,\text{V}

. If the current in the primary of the transformer is

5\,\text{A}

and its efficiency is

90\%

, the output current is: (1)

20\,\text{A}

(2)

40\,\text{A}

(3)

45\,\text{A}

(4)

25\,\text{A}