Answer: 1/r.
- A 1/r
- B 1/r²
- C 1/r³
- D r
Correct answer: A. 1/r
Explanation: For a line charge, E = λ/2πε₀r, so E ∝ 1/r.
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.