Answer: zero.
- A zero
- B kQ/R²
- C kQ/r²
- D a nonzero constant
Correct answer: A. zero
Explanation: In a conductor at equilibrium the field inside is zero; all excess charge resides on the surface.
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.