Which of the following is a conductor of electricity?

• A. Plastic
• B. Copper
• C. Rubber
• D. Wood

Answer: (B)

Electric conduction happens when a material allows electrons to move freely under an applied voltage. In metals, electrons aren’t bound to a single atom; they form a loosely bound “sea” that can glide through the lattice, letting current flow easily. Copper is a prime example because it has many free electrons and relatively low resistance to their movement, so electrical current passes through it with minimal loss. That makes copper an excellent conductor and the material of choice for wiring.

Plastic, rubber, and wood do not conduct electricity under normal conditions because their electrons are tightly bound and resist movement, giving them high resistance. They’re used as insulators to prevent unwanted current flow. Only in special cases (like moisture or damage) might they conduct a little, but not in the normal sense.