Answer: -1.8 × 104 V.
- A +1.8 × 104 V
- B -9.0 × 103 V
- C -1.8 × 104 V
- D -3.6 × 104 V
Correct answer: C. -1.8 × 104 V
Explanation: At the zero-field point, the distances are 1 m and 2 m. V = k(2 × 10-6/1 - 8 × 10-6/2) = -1.8 × 104 V.
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.