0:07 hello friends today we are learning
0:09 about the heat and the transfer of the
0:12 heat in science heat is a form of the energy
0:13 energy
0:16 it is also known as thermal energy it is
0:19 a sum of the kinetic energy of atoms or
0:22 molecules of any particular given substances
0:24 substances
0:27 in thermodynamics heat is energy that is
0:30 moved between two things one of them has
0:33 a higher temperature than the other heat
0:36 always flow from the hotter body to the
0:38 colder body here
0:40 we will be learning the various ways of
0:42 the heat transfer like the conduction
0:45 convection and the radiation
0:48 let's understand the conduction by a
0:50 simple activity we need some materials
0:54 like a copper rod small nails a candle a
0:57 matchbox and a wooden stand fix the nail
0:59 on the copper rod with the help of the
1:01 candle bags as shown
1:03 maintain a distance of about two
1:05 centimeters between two nails
1:07 insert the other end of the copper rod
1:10 into the paper roll as shown
1:12 adjust the height of the candle
1:14 accordingly to the height of the wooden stand
1:15 stand
1:18 light the candle and place it under one
1:22 end of the copper rod so that this end
1:25 will get heat from the candle flame [Music]
1:40 observe some time and see what's
1:41 happened to the nails
1:44 after a few seconds the first nail force down
1:46 down [Music]
1:53 as you continue to provide the heat to
1:56 the copper rod after some time second
1:58 nail falls down
2:00 and after that the subsequent nails
2:02 falls down
2:03 as well [Music]
2:10 [Music]
2:13 if you observe carefully you will notice
2:16 that the nail nearest to the candle
2:19 flame falls down first then the second
2:21 nail and the so on
2:23 when we provide heat to the one end of
2:25 the copper rod the wax used to fix the
2:27 nails to the copper rod
2:30 melts down and hinge the nail falls off
2:33 the copper rod get heat from the candle
2:35 and this heat transfer from hotter end
2:37 of the copper rod to the colder end of
2:40 the copper rod hence the nail falls down
2:43 subsequently from the copper rod this
2:45 process of the heat transfer is known as
2:48 the conduction of the heat in conduction
2:50 the transfer of heat from one atom to
2:53 another is accomplished by the direct
2:57 contact of the atom of the copper rod
2:59 now let's understand another method of
3:01 the heat transfer it is known as a
3:03 convection method take a small glass
3:05 bottle and tie the thread to the neck of
3:08 the bottle then put a few drops of the
3:11 ink or food colour in it fill this glass
3:24 [Music]
3:27 slowly insert the glass bottle into the
3:30 container using a thread and observe
3:33 what is happening inside [Music]
3:38 [Music]
3:40 you can see the beautiful cloud of the
3:42 colored water coming from the glass
3:45 bottle why it is happening the density
3:47 of the hot water is less than the
3:49 density of the cold water when we
3:51 submerge the hot water bottle in the
3:54 cold water due to the lower density of
3:57 the hot water it goes towards the upper
4:00 side in the cold water container here
4:02 with the help of the color you can see
4:04 the path of the hot water
4:06 this process of the heat transfer is
4:09 known as a convection in this convection
4:12 process of heat transfer the movement of
4:14 the heat by fluid
4:18 such as water or ear is convective you
4:21 can make some changes to the experiment
4:23 instead of using the single bottle you
4:26 can use three bottles and repeat the
4:28 above activity if you fill the three
4:31 bottles with three different colors then
4:35 you will see different color coming from the
4:36 the bottles
5:10 after some time when the temperature of
5:12 the water inside the water and outside
5:15 the bottle gate equalize then you will
5:18 not find any colorful clouds in the
5:19 water tank
5:22 now let's understand one more method of
5:24 the transfer of heat it is known as
5:26 radiation here we are using the
5:29 radiometer that we got from the market a
5:32 radiometer is a device that measures the
5:35 power of electromagnetic radiation in
5:37 this radiometer the veins rotate when
5:40 exposed to the light with the faster
5:42 rotation for more intense light
5:44 providing a qualitative measurement of
5:46 the electromagnetic radiation intensity here
5:47 here
5:50 you will find heat transfer without any
5:53 medium this type of the heat transfer is
5:57 known as radiation here you must observe
5:59 the transfer of the heat by the
6:01 electromagnetic waves this type of the
6:04 heat transfer is known as a radiation i hope
6:05 hope
6:08 you must enjoy the above activities
6:13 involved with heat and the heat transfer
6:15 some of these activity you may easily
6:17 perform in your home
6:20 please do all of our activities under
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