For demonstrating the differences in the thermal conductivity of five different metals - brass, copper, aluminium, mild steel and stainless steel. These 5 metal rods are equally spaced around a brass hub, and have a small recess at the other end for holding paraffin wax. The brass hub has a metal rod and insulating handle. On heating the central hub, the wax contained in the cavities of different metals melts at different times, showing their different thermal conductivities.
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