Question

Three charges 2q, − q, − q are located at the vertices of an equilateral triangle. At the centre of the triangle

1. The field is zero but potential is non - zero
2. The field is non - zero but potential is zero
3. Both field and potential are zero
4. Both field and potential are non - zero

Answer 1

Correct Answer - Option 2 : The field is non - zero but potential is zero

Obviously, from charge configuration, at the centre electric field is non - zero.

Potential at the centre due to 2q charge \({V_{2q}}\; = \;\frac{{2q}}{{4\pi {\epsilon_0}r}}\)

Potential at the centre due to - q charge \({V_{\; - \;q}}\; = \;\frac{{\; - \;q}}{{4\pi {\epsilon_0}r}}\)

Total Electrical potential: V_2q+V _{-  q}+V _{- q} = 0