question_answer

What is the electric potential at the centre of the square?

A)  zero       

B)  \[kq/a\sqrt{2}\]

C)  \[kq/{{a}^{2}}\]                 

D)  None of these

Correct Answer: A

Solution :

                          Electric potential at centre \[\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{Q}{\sqrt{2}a}+\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{Q}{\sqrt{2}a}-\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{Q}{\sqrt{2}a}-\frac{1}{4\pi {{\varepsilon }_{0}}}-\frac{Q}{\sqrt{2}a}=0\]