A step-down transformer is used on a `1000 V` line to deliver `20A` at `120V` at the secondary coil. If the efficiency of the transformer is `80%` the current drawn from the line is.

Options

A. `3 A`
B. `30A`
C. `0.3A`
D. `2.4 A`

Answer

A

Explanation

`eta=(Output)/(Input) implies 80/100 =(20xx20)/(1000xxi_(l))`
`implies i_(l)=(20xx120xx100)/(1000xx80)=3A`.