Question

Determine the electric potential at point P due to two point charges each of charge $+Q$, with one point charge being at a distance R and the other being at a distance $2R$ :

• A. $\frac{3Q}{8\pi {ϵ}_{0}R}$
• B. $\frac{2Q}{12\pi {ϵ}_{0}R}$
• C. $\frac{3Q}{12\pi {ϵ}_{0}R}$
• D. $\frac{2Q}{8\pi {ϵ}_{0}R}$

Answer 1

The correct option is A $\frac{3Q}{8\pi {ϵ}_{0}R}$

Electric potential at point P due to charge at distance $R$, $V_1=\frac{q}{4\pi {ϵ}_{o}R}$

Electric potential at point P due to charge at distance $2R$, $V_2=\frac{q}{8\pi {ϵ}_{o}R}$

Net electric potential at p, $V_p=V_1+V_2=$ $\frac{q}{4\pi {ϵ}_{o}R}+$ $\frac{q}{8\pi {ϵ}_{o}R}=$ $\frac{3q}{8\pi {ϵ}_{o}R}$