Which statement describes an insulator?

• A. Material with high resistance that resists current flow, such as plastic
• B. A material that conducts best
• C. A material that stores electrical energy
• D. A material that amplifies current

Answer: (A)

An insulator is a material that resists the flow of electric current because it has high resistance. This is what keeps current from moving freely through the material, which is why plastic is a common insulator used to coat wires and prevent shocks. The other descriptions point to different electrical properties: a material that conducts best is a conductor; a material that stores electrical energy refers to devices like capacitors; a material that amplifies current relates to active components that boost current. So, the statement about high resistance and resisting current flow best identifies an insulator and explains why it’s used for safety and control in electrical systems.