Unlike charges ________________.

• A. Repel
• B. Neutral
• C. Cancel
• D. Attract

Answer: (C)

Opposite charges pull toward each other. When two charges have opposite signs, the electric force between them is attractive: each charge feels a pull toward the other along the line joining them. This comes from Coulomb’s law, which says the force magnitude goes as k|q1 q2|/r^2 and points along the line connecting the charges. Since q1 and q2 have opposite signs, the force vectors on both charges point inward toward the other charge, producing attraction.

The other ideas don’t fit this situation: like charges repel each other, so they push apart; neutral doesn’t describe an interaction with another charge, it means no net charge but doesn’t specify the force between two charges; and “cancel” isn’t a standard description of how charges interact.