Answer: their fields are equal and oppositely directed.
- A their fields are equal and oppositely directed
- B their potentials cancel completely
- C the charges produce no electric field
- D the midpoint is an equipotential point only
Correct answer: A. their fields are equal and oppositely directed
Explanation: At the midpoint, the two electric fields have equal magnitudes and opposite directions, so their vector sum is zero.
Field lines always point from positive to negative charge, are denser where the field is stronger, and never cross; an isolated positive charge has lines radiating symmetrically outward, while a dipole's lines curve from the positive to the negative charge.
Concept context
Coulomb's law, electric field, potential, capacitors, Gauss's law.