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A step-down transformer is used on a 100...

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.

A

`3A`

B

`30A`

C

`0.3A`

D

`2.4A`

Text Solution

Verified by Experts

The correct Answer is:
A
`eta=(P_(S))/(P_(P))=(I_(S)*e_(S))/(I_(P)*e_(P))`
`I_(P)=(I_(S)*e_(S))/(eta*e_(P))=(20xx120)/(0.8xx1000)=3A`
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