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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

30 A

C

0.3A

D

2.4 V

Text Solution

Verified by Experts

The correct Answer is:
A
`eta = ("Output Power")/("Input Power")`
`rArr 80/100 = (20 xx 120)/(1000 xx I)`
`rArr I=(20 xx 120xx100)/(1000 xx I)`
`rArr I = (20 xx 120 xx 100)/(1000 xx 80) = 3A`
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