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igcse physics notesprinted 83 · PDF 83
124 pagesrevision 46936
printed 83 · PDF 83
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83
Factors affecting the rate of Radiations:
Surface Area: More the surface area, high is the rate of absorption of heat.
Surrounding Temperature: High is the surrounding temperature, more is
the rate of absorption of heat. Heat travels from high temperature to low
temperature and its speed depends on the difference in temperature. When
the temperature difference is more, the rate of heat transfer will be more
and vice versa.
Colour:
Dull black surfaces are good absorbers and emitters of heat while silver
shiny surfaces are bad absorbers and emitters of heat; therefore, when we
need to maintain an object's temperature and prevent it from absorbing
heat from surrounding then we coat it by silver as radiations reflect on the
surface. On the other hand when we need to heat up a thing quickly we
coat it with dull black as it absorbs and emits heat quickly.