Heat transfer Flashcards
Expansion is?
When an object is heated up, the particles gain energy and vibrate more vigorously, moving further apart from each other and thus increasing in volume
Contraction is?
When the temperature decreases, the particles lose energy and vibrate less, moving closer to each other and thus decreasing in volume.
Bimetallic strip?
- A bimetallic strip is a strip of
two different metals. - When two different metal strips
are fixed together, the strip will
bend when heated or cooled. - Brass is better conductor of heat as compared to steel, thus expanding more than steel,
and becomes longer and the
strip will bend towards the steel. The bending is
reversed when the strip cools.
SUMMARY OF THIS is that when heated, the bimetallic strip will bend towards the poorer conductor of heat, vice versa.
Answer format for bimetallic strip
When __________ , the bimetallic strip will __________ and
bend __________ the contact. The circuit is then
__________ , current _____________ and the _______________ stops. As it __________ , the bimetallic strip will
return to its original position and the process repeats.
Heat transfer definition?
Heat always transfers from an area of higher temperature to an area of lower temperature.
Diff types of heat transfer?
Conduction, convection, radiation
What is conduction
Conduction is the transfer of heat without the movement of the medium but requires the use of a medium
What is convection?
Convection the transfer of heat from one place to another through the movement of the medium itself
convection current
What is radiation?
Radiation is the transfer of energy from a hotter body to a cooler body without the need for a medium.
why does heat travel faster through solids?
In solids, the molecules are closer together
than in liquids or gases. Therefore
molecules can collide with neighboring
molecules more quickly and transfer energy
more quickly.
