Heating In Current-Carrying Wire
To show the conversion of electrical energy into heat.
Sagging wire apparatus.
Push to attach 110 VAC to wire, heating the wire and causing it to become longer and sag. The marker◙hanging in the center of the wire indicates the sag.
Richard C. Hitchcock, Mark W. Zemansky, Demonstrating Linear Thermal Expansion By Using the Catenary, AJP 13, 329-333, (1945).