Experiment to investigate the....

Absorption of radiation by a black(dull) and silvery surface

Appratus needed: 1. 2 temperature sensors
2. data logger
3.100w bulb
4.aluminium foil

Procedures: 1. place the 2 sensors at equal distance away from the 1002 bulb.
2. connect the 2 sensors to the data logger where a graph of temperature
against time will be plotted.
3.one sensor is blackened and the other wrapped with aluminium foil.
4.switch on the sensors and the light bulb.
5 .after some time, switch off the light bulb.


conclusion:1. the blackened sensor shows a higher temperature recorded.
2.therefore, black(dull) surfaces are better absorbers of radiation.



Emission of radiationby a black(dull) and slivery surface

Appratus needed: 1. temperature sensors
2.data logger
3. 2 identical tins(one painted black and one with silvery surface)
4. boiling water maintained at 100 c.


Procedures: 1.place the temperature sensors into the tins filled with boiling water.
2.one tin is blackened on the surface and the other with silvery surface.
3. start the data logger
4.stop the data logger after some time
5.the graph is plotted with temperature against time.


conclusion: 1. the graph shows that the temperature of water in the blackened tin drops
faster compared to the water in the silvery tin.
2.the blackened surface is a better emitter of radiation.