Which material has low resistance?

Which material has low resistance?

• A. Electrical Insulator
• B. Electrical Conductor
• C. Capacitor
• D. Semiconductor

Answer: (B)

Low resistance means a material lets current flow easily. This happens in conductors, which have many free electrons and low resistivity. The resistance of a piece of material follows R = ρL/A, so for a given shape, a material with low resistivity like copper or aluminum offers a much smaller R than insulators. Insulators tightly bind electrons, giving them high resistance and making current hard to push through. Semiconductors sit between conductors and insulators, with resistance that can vary with temperature, light, or doping. A capacitor isn’t a material at all but a device that stores charge between two plates; in DC it acts like an open circuit once charged and does not provide a low-resistance path. So, the material with low resistance is the conductor.

Low resistance means a material lets current flow easily. This happens in conductors, which have many free electrons and low resistivity. The resistance of a piece of material follows R = ρL/A, so for a given shape, a material with low resistivity like copper or aluminum offers a much smaller R than insulators. Insulators tightly bind electrons, giving them high resistance and making current hard to push through. Semiconductors sit between conductors and insulators, with resistance that can vary with temperature, light, or doping. A capacitor isn’t a material at all but a device that stores charge between two plates; in DC it acts like an open circuit once charged and does not provide a low-resistance path. So, the material with low resistance is the conductor.