In this experiment (Blackbody Thermal Emission), we will be determining whether the thermal emission gets affected by colour in an enclosed environment. As we already know, the black body absorbs heat more rapidly than any other colour. Therefore, we will be finding whether the black body emits and cools at a higher rate.
To determine whether the thermal emission gets affected by the colour in an enclosed environment.
1. Black body absorbs heat more rapidly than any other colour.
2. Every object in nature radiates energy in the form of electromagnetic radiation. But the black body absorbs all the light or energy falling on it and transmit none.
3. Thermal radiation and black-body radiation are the same.
1. Two aluminium blocks,
2. Balck paint,
3. Two mercury candy thermometers,
4. Two cardboard boxes,
5. Two wooden dowel structures,
Step 1: Use two aluminium blocks to perform this experiment as they have a large amount of mass that cools down slowly. And this would help in measuring the temperature easily.
Step 2: Both blocks should be uncoated.
Step 3: Drill a hole on each of the aluminium blocks.
Step 4: Paint one of the aluminium block black colours.
Step 5: Construct two environments, heating and cooling, to perform this experiment. Remember to control convection and conduction in these environments. Radiation will only be the variable.
Step 6: To control conduction and convection use two wooden dowel structures and two boxes of cardboard. These boxes must have closeable openings for measuring temperature readings.
Step 7: Put a mercury candy thermometer in the drilled hole of each of the aluminium boxes.
Step 8: Check the temperature every five minutes of intervals until the graph line of recorded temperature does not become horizontal.
1. In all three experiments, we observed that the aluminium block coated with black paint cools down faster as compared to the aluminium block coated with non-black colour. And, this proved our hypothesis.
2. We also observed that the black aluminium block cooled down at the rate of twenty-five Celsius or more than the non-black aluminium block.
1. The result of this experiment supported our hypothesis. But between the two blocks, the black aluminium block caused a difference of 25 degrees celsius at the time of the greatest rate of change.
2. This application can be used where there is a requirement for efficient cooling.
3. Although we are aware of this property, while looking around for its application, barely any were found.
1. Black paint should be flat.
2. Record your observation carefully.
3. Wear gloves.
4. Wash your hands carefully.
In this experiment, we determine whether the black material emits and cools down more rapidly than non-black material.
Q.1 What was the aim of your experiment?
ANS. To determine whether the thermal emission gets affected by the colour in an enclosed environment.
Q.2 Which colour of aluminium block got heated more rapidly?
ANS. The Aluminium block, painted with black, got heated more rapidly.
Q.3 Which colour of aluminium block cooled down more rapidly?
ANS. Aluminium blocks painted with black colour cooled down rapidly.
Q.4 Why is there barely any application of this project?
ANS. Black materials cool down rapidly but it also gets heated up rapidly which does not make them suitable for any use.
Q.5 What was your hypothesis?
ANS. Our hypothesis was that the black body emits and cools at a higher rate.
An Indian nuclear physicist, founding director, and professor of physics at the Tata Institute of Fundamental Research.