CONDUCTIVITY OF DIFFERENT MATERIALS

Suppose an experiment is conducted by taking a container with water inside having rods of different materials attached to it. The rods have a coating of wax on them, the length of the wax is same on each rod.

Wax layer on copper melts more than wood

Now if a heating elements introduced into the water and after sometime the water will be heated. Simultaneously the wax will start melting and dripping from the rods. The wax will drip quickly from the copper rod and the amount of dripping will decrease successively for each rod, being least for the wooden one.

This is because each element has different conductivity.

Similarly If we touch the metal handle utensil we instantly remove our hand as we suddenly touched something hot.
Metals being good conductors of heat, transfers heat from one end to the other very quickly. Hence, the metal handle becomes too hot to touch.

Now if we touch the plastic or wooden handle utensil we'll be able to lift it from the oven.Plastic and wood are insulator (a bad conductor of heat) and hence even though the metallic part of the utensil gets heated, the handle remains cold enough to be touched.