arrange the charges +q,+q & -qusing distances r,2r ,2r to get a system with zero potential ?
Kindly refer to the link given below for an answer to a similar query :
https://www.meritnation.com/ask-answer/question/pls-hepl-me-with-this-question-arrange-the-three-charges-q/electrostatic-potential-and-capacitance/1048760
https://www.meritnation.com/ask-answer/question/pls-hepl-me-with-this-question-arrange-the-three-charges-q/electrostatic-potential-and-capacitance/1048760