Question

Two identical positive charges are 0.6 meters apart. Which of the following is true about the electric field and potential at the point which is directly in-between the two?

• A. The electric field and potential both are zero
• B. The electric field and potential both are positive numbers
• C. The electric field is a positive number while the potential is zero
• D. The electric field is zero while the potential is a positive number

Answer 1

Answer: (D)

The electric field is zero while the potential is a positive number

As the charges are identical so the fields at mid point between them due to them will be same and opposite. (as $E=kq/r^2$) Thus, electric field at mid point of them will be zero.

The potential at mid point of them is $V=kq/0.3+kq/0.3=2kq/0.3$. So it has positive value.