Answer: 9.0 × 103 V.
- A 9.0 × 103 V
- B 1.8 × 104 V
- C 4.5 × 103 V
- D 3.6 × 104 V
Correct answer: A. 9.0 × 103 V
Explanation: For a short dipole, V = kp cosθ/r2. On the axis cosθ = 1, so V = 9 × 109 × 4 × 10-8/0.22 = 9.0 × 103 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.