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Two charges q and 3q are separated by a distance 'r' in air. At a distance x from charge q, the resultant electric field is zero. The value of x is :
(3) r(1+ 3)
like charges the null point lies between them, nearer the smaller charge q
Eq=E3q: kqx2= k(3q)(r-x)2
(r-x)2=3x2 r-x= 3x
x= r1+ 3
Answer: (3)
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