A copper bar and a wooden bar are connected together. A strip of paper is wrapped tightly around the point where they join. The middle of the bar is then heated strongly for a short period, and the paper turns brown on only one side. Which side turns brown, and what does this indicate about wood and copper?
- Abrown side: copper; wood: conductor; copper: insulator
- Bbrown side: copper; wood: insulator; copper: conductor
- Cbrown side: wood; wood: conductor; copper: insulator
- Dbrown side: wood; wood: insulator; copper: conductor