How does a conductor differ from an insulator in terms of electrical current?

• A. Conductors block current; insulators let current flow.
• B. Conductors allow current easily; insulators resist current.
• C. Conductors store electricity; insulators convert it.
• D. Conductors are always metal; insulators are always nonmetal.

Answer: (B)

Materials differ in how easily electrons can move when a voltage is applied. A conductor has loosely bound electrons that can drift and carry charge readily, so an applied voltage produces a noticeable current through the material. An insulator has electrons that are tightly bound, so they resist movement and only a very small current flows even with a voltage. That’s why copper wires conduct electricity, while rubber or plastic insulate.

The other statements mix up what conductors and insulators do: blocking current is the opposite of what conductors do; storing electricity or converting it describes other ideas not about current flow; and whether something is metal or nonmetal isn’t a reliable rule for its conducting behavior.