Convection, Conduction And IR Radiation Flashcards
What are the best materials for conducting heat?
Metals
Metals are known for their excellent thermal conductivity.
What is the state of matter where objects must be in contact for heat transfer?
Solids
Heat transfer in solids occurs through conduction.
What type of radiation is emitted by all objects?
Infra-red radiation
The hotter the object, the more infra-red radiation it emits.
What is the effect of heat on water particles near a heat source?
They gain thermal energy and expand
This causes them to rise, creating convection currents.
What is the primary mechanism of heat transfer in gases?
Convection
Convection is the movement of heat through fluids.
What is evaporation in the context of heat transfer?
A transfer of thermal energy from a liquid to the surroundings
Evaporated particles carry thermal energy away, cooling the remaining liquid.
What is the role of fiber in reducing heat transfer?
It traps air particles, acting as a good insulator
This minimizes convection currents.
What surfaces are the best emitters of heat radiation?
Matt black surfaces
They are also poor absorbers of heat radiation.
How does a vacuum flask keep contents at stable temperatures?
By minimizing conduction, convection, and radiation
It has shiny surfaces that reflect heat and an insulating layer to prevent convection.
What type of heat transfer is primarily prevented by the design of a vacuum flask?
Convection
The vacuum layer prevents air movement that would transfer heat.
Fill in the blank: Black surfaces are the best _______ of heat radiation.
emitters
Conversely, they are poor absorbers.
True or False: White surfaces are good conductors of heat.
False
White surfaces are not effective conductors of heat.
What type of radiation can pass through double-glazed windows?
Light
Light can travel through glass, while heat transfer is minimized.
