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.
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.