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A charge q is placed at the centre of th...

A charge q is placed at the centre of the line joining two equal charges Q. The system of the three charges will be in equilibrium if q is equal to:

A

`Q//4`

B

`-Q//4`

C

`-Q//8`

D

`Q//8`

Text Solution

Verified by Experts

The correct Answer is:
B
For equilibrium net force must be zero
`i.e." "1/(4piin_(0))(Qq)/((r//2)^(2))+1/(4piin_(0))(Q Q)/r^(2)=0`
`therefore" "q=(-Q)/4`
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