Question

4. Two charges, +3Q and -Q, are separated by 4 cm. Is there a point along the Region I Region I1 Region III line passing through them (and a finite distance from the charges) where the net electric field is zero? If so, where? How about any location that is not collinear with the charges. +30 -0

Please show all work and steps!

Answer 1

let us consider that the NULL point is observed right side of - Q charge, at a distance 'd' from it.

in order to get NULL point at distance 'd' both the values of electeic field due to +3Q and - Q charges must be equal in order to balance each other, so

k (3Q) / ( 4 + d ) ^2 = k Q / d^2

sqrt (3) = 4/d +1

d = 5.464 cm

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net electric field observed to be zero

at 5.464 cm from - Q charge

at 9.464 cm from +3Q charge

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since the point observed to the right side of - Q so it lies in region III

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no NULL point ever observed on any non collinear point.

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do comment in case any doubt, will reply for sure.. Goodluck