Answer: E = kQ/r2.
- A E = kQ/r
- B E = kQ/r2
- C E = kQ*r2
- D E = kQ2/r2
Correct answer: B. E = kQ/r2
Explanation: E = kQ/r2. Direction: away from positive charge, toward negative charge.
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.