MTTC Upper Elementary (3–6) Education – Science and Social Studies (124) Practice Test

Electricity moves more easily through some materials than others. A conductor has low resistance, so electric charges can flow through it readily. An insulator has high resistance, which greatly slows or blocks the flow of charges. The statement that conductors allow current to flow and insulators resist current captures this essential difference. For example, metal wires are conductors, letting current pass, while rubber coatings on wires act as insulators to keep that current from escaping and to protect people. The other choices mix up the roles or suggest there’s no difference, which isn’t accurate.