Four point charges $- Q,\ - q,\ 2q$ and $2Q$ are placed, one at each corner of the square. The relation between $Q$ and $q$ for which the potential at the centre of the square is zero is

Question

Dr. Abubacker · Accepted Answer

(a) [image:1_image376.emf]
Let the side length of square be $''a''$ then potential at centre $O$ is
$V = \frac{K( - Q)}{\left( \frac{a}{\sqrt{2}} \right)} + \frac{k( - q)}{\frac{a}{\sqrt{2}}} + \frac{k(2q)}{\frac{a}{\sqrt{2}}} + \frac{k(2Q)}{\frac{a}{\sqrt{2}}} = 0$
$= - Q - q + 2q + 2Q = 0 \Rightarrow Q + q = 0 \Rightarrow Q = - q$

Q. Four point charges $- Q,\ - q,\ 2q$ and $2Q$ are placed, one at each corner of the square. The relation between $Q$ and $q$ for which the potential at the centre of the square is zero is

Explanation

Reviewed by Dr. Abubacker

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