Answer: -8 × 10-7 C.
- A +8 × 10-7 C
- B -8 × 10-7 C
- C +5 × 10-7 C
- D -5 × 10-7 C
Correct answer: B. -8 × 10-7 C
Explanation: Each electron has charge -1.6 × 10-19 C. Therefore q = -5 × 1012 × 1.6 × 10-19 = -8 × 10-7 C.
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.