A copper bar and a wooden bar are attached together. A strip of paper is wrapped tightly round the point where they meet. The bar is then heated strongly in the middle for a short time, and the paper turns brown on only one side. Which side turns brown, and what does this reveal 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