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A thin semi-circular ring of radius r ha...

A thin semi-circular ring of radius r has a positive charge q distributed uniformly over it. The net field `vecE` at the centre O is

A

`q/(2pi^2epsi_0r^2)hatj`

B

`q/(4pi^2 epsi_0r^2)hatj`

C

`-q/(4pi^2 epsi_0r^2)hatj`

D

`-q/(4pi^2 epsi_0r^2)hatj`

Text Solution

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The correct Answer is:
A
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