What is black body radiation
▹ Radiation emitted by an object due the
increment of their temperature compare
to its surrounding is called Black-Body
radiation and that object is known as
▹ Sun is perfect example of black-body
because it can Emit radiation of any
Effect of Temperature
▹ Black body absorbs the radiations .
▹ If surrounding is cold and black
body is hot due to absorbing radiations
so the heat energy will flow from the
black body to surrounding in form of
electro magnetic radiations.
▹ When black body can absorb the radiation in limits and it reflect the left radiation back .
▹ This reflected radiation is in wave form , so there are radiations which have different
wave length and frequency.
▹ That is the reason why we can see different colours easily.
▹ Scientist did an experiment for this , they gave heat energy to a metal box and at
different temperature that box gains different radiation. Because of the different
radiation that box changed colour .
▹ From performing the experiment scientist noted that if we
increase temperature , black body will radiate higher
▹ It means if we increase the temperature the wave length of
the radiation will decrease
▹ After this theory famous scientist Planck gave a statement “
energy is discontinuously radiated in discrete wave
packets.” snf equation between energy and frequency of
photons . Which is E= hµ where h is Planck’s constant.
(6.626 x 10^-34)
▹ We should wear black dresses during winter because subject which is
black can absorb more radiation than others.
▹ To analysis the planet’s heat and atmosphere from earth.
▹ Red color scatters the least as it has the greatest wavelength. So red light
is able to travel the longest distance through the fog, rain, and air
particles. That is why the red color is used in danger signals; not because
it is more attractive and common.
▹ Black body can gain energy from light so there are blue lights
In freezers so products cant gain the energy or heat
We use radium coloured straps on road breakers because we
can see them by reflected radiation of the lights . Which leads
to less accidents.
Blue led to scan finger prints and doctors also use to check up
With Blue Dim light we can save electricity because blue color
needs less energy , it has less frequency and also its not so
bright so as dim light it is perfect.