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A step-down transformer is connected to ...

A step-down transformer is connected to main supply `200V` to operate a `6V`, `30W` bulb. The current in primary is

A

3A

B

0.15 A

C

1.5 A

D

0.3 A

Text Solution

Verified by Experts

The correct Answer is:
B
Output power across secondary `=V_(S)I_(S)`
`rArr 30=6I_(S)`
`rArr I_(S)=5A`
Again, `(V_(S))/(V_(P))=(I_(P))/(I_(S))`
`rArr (6)/(200)=(I_(P))/(5)`
`rArr I_(P)=(5xx6)/(200)=(3)/(20)`
`=0.15A`
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