Question

Three identical charges of charge $q$ are placed at the three corners of an equilateral triangle. The electric potential $V$ and the intensity of the electric field $E$ at the centroid $\text{O}$ will be

• A. $V=0$ , $E\ne 0$
• B. $V\ne 0$ , $E=0$
• C. $V\ne 0$ , $E\ne 0$
• D. $V=0$ , $E=0$

Answer 1

The correct option is B $V\ne 0$ , $E=0$



$E_1=E_2=E_3$

$E_{net}=0$

Angle between any two field is ${120}^{\circ }$. Hence their vector sum is zero.

Potential at the centre is,

$V=V_1+V_2+V_3$

$V=3\left(\frac{1}{4\pi {\epsilon }_0}\right)\frac{q}{a}$

i.e $V\ne 0$

Hence, (b) is the correct answer.