7th Class Science Heat Conductors of Heat

     Conductors of Heat

A device, which can conduct heat is called heat conductor. A rod of iron conducts heat, hence it is heat conductor. A piece of wood does not conduct heat. Therefore is called insulator or bad conductor or poor conductor of heat. The food preparation is possible due to conduction of heat. Mostly, aluminum or iron jar is used for the preparation of food, as they are good conductor of heat.

Look at the following pictures of conductor of heat

An iron rod is heated                                      Copper wire                                                

Steel                                                                      Aluminum  

     Knife  

In the above figure (1), an iron rod is heated by a burning candle. Iron rod is a good conductor of heat because heat is transferred from one end to other end. The property of the conductor is called conduction. In the figure (2), copper wire is the conductor of heat because, it transfers heat from one end to other.

In the figure (3), alloy steel is the conductor of heat, therefore, utensils made of steel are widely used for the preparation of food. Aluminum is also a good conductor of heat and therefore, used as utensils for the food preparation.

     Copper and Iron are the good conductors of heat. Which one of the following is not a good conductor of heat?

(a) Soil

(b) Aluminum

(c) Tungsten

(d) Steel

(e) None of these

Answer: (a)

      Why aluminum metal is used for making utensils for food preparation?

(a) Because it is a good insulator of heat               

(b) Because it is a good conductor of heat

(c) Because it is good conductor of electricity

(d) All of these

(e) None of these

Answer: (b)