Answer: sigma / epsilon 0.
- A sigma x A / epsilon<sub>0</sub>
- B sigma / epsilon<sub>0</sub>
- C sigma / (2 epsilon<sub>0</sub>)
- D 2 sigma / epsilon<sub>0</sub>
Correct answer: B. sigma / epsilon<sub>0</sub>
Explanation: For infinite parallel plates: E = sigma/epsilon<sub>0</sub>. Each plate gives sigma/(2epsilon<sub>0</sub>); combined = sigma/epsilon<sub>0</sub>.
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.