Question

State the factors on which the quantity of heat conducted through a solid bar depend

Answer 1

Conduction transfers heat through material directly, through contact. Thanks to physics, we know that conduction is affected by temperature difference, the area of conduction, the distance the heat must travel, and the amount of time that passes.

Take a look at the metal pot in the figure and its metal handle; the pot has been boiling for 15 minutes. Would you want to lift it off the fire by grabbing the handle without an oven mitt? Probably not. The handle is hot because of conduction of heat through the metal handle.


On the molecular level, the molecules near the heat source are heated and begin vibrating faster. They bounce off nearby molecules and cause them to vibrate faster. That increased bouncing is what heats a substance.

You have to take different properties of objects into account when you want to examine the conduction that takes place. If you have a bar of steel, for example, you have to consider the bar’s cross-sectional area and length, along with the temperature at different parts of the bar.


Take a look at the second figure, where a bar of steel is being heated on one end and the heat is traveling by conduction toward the other side. Can you find out the thermal energy transferred? No problem.