Describe a simple experiment to differentiate good conductors from bad conductors? answer my question I will Mark u a brainlist
Answers
Answer:
Take a set of rods such that each is made of a different metal. The rods must be coated with wax. This can be done by one of the following methods:
Take the rods and lay them in a chilled tin tray containing molten paraffin-wax. Remove quickly, hold vertically to allow the excess wax to drain off and set them aside.
Paint each rod with a paintbrush dipped in very hot molten wax. This produces an uneven, thick coating of wax, which must then be thinned by blowing a Bunsen flame up and down the rod. (This is a poor method, only successful in very skilful hands).
Fill the water bath with hot water. Dip all the rods together keeping space between them. Note how far along the rods the wax has melted when the setup reaches a steady state.
Notes:
Note that the speed at which a particular temperature (such as the melting point of wax) travels along a bar when one end is heated is essentially the speed of the 'temperature waves'. This involves specific heat capacity and density as well as conductivity. Thus a rod of lead makes a quick start in the race although it is a poor conductor, the wax-melting will not have travelled far when a steady state is attained.
The experiment involves heat losses from the surface of the rod. If for a steady state, the distance from the heated end to the melting point of the wax is twice as great for rod A as for rod B, then rod A has only half the temperature gradient but twice the surface area for heat losses. So rod A must have four times the conductivity of rod B.