-->

Electrostatic Potential And Capacitance

Question
CBSEENPH12039930

Four electric charge +q, +q, -q and -q  are placed at the corners of a square of side 2L (see figure). The electric potential at point A, mid-way between the two charges + q and +q, is

  • fraction numerator 1 over denominator 4 πε subscript straight o end fraction space fraction numerator 2 q over denominator L end fraction space open parentheses 1 space plus space fraction numerator 1 over denominator square root of 5 end fraction close parentheses
  • fraction numerator 1 over denominator 4 πε subscript straight o end fraction space fraction numerator 2 q over denominator L end fraction space open parentheses 1 space minus space fraction numerator 1 over denominator square root of 5 end fraction close parentheses
  • zero

  • fraction numerator 1 over denominator 4 πε subscript straight o end fraction space fraction numerator 2 q over denominator L end fraction space open parentheses 1 space plus space square root of 5 close parentheses

Solution

B.

fraction numerator 1 over denominator 4 πε subscript straight o end fraction space fraction numerator 2 q over denominator L end fraction space open parentheses 1 space minus space fraction numerator 1 over denominator square root of 5 end fraction close parentheses straight V space equals space fraction numerator 1 over denominator 4 πε subscript 0 end fraction straight q over straight r
Here comma space straight V space equals space 2 straight V subscript plus ve end subscript space plus 2 straight V subscript negative ve end subscript
straight V space equals space fraction numerator 1 over denominator 4 πε subscript straight o end fraction open square brackets fraction numerator 2 straight q over denominator straight L end fraction space minus space fraction numerator 2 straight q over denominator straight L square root of 5 end fraction close square brackets

straight V space equals space fraction numerator 2 straight q over denominator 4 space πε subscript straight o straight L end fraction open parentheses 1 space minus space fraction numerator 1 over denominator square root of 5 end fraction close parentheses

Some More Questions From Electrostatic Potential and Capacitance Chapter