 and people can join in between. So Pankaj, whenever you are ready, so we are good to go. We are live. So shall we start? Yes, yeah. Okay, okay. Hello and Namaste. Once again, I'm Suravi. I welcome you to Homey Baba Vigyan Sikhsha Kendra Dwarah Aayujit Steamboat Talk series. Steam means science, technology, engineering, arts, and mathematics. So our Steamboat, every Monday, Sunday, at 11 o'clock, is on its way to a fun episode to reach you. If you are joining us for the first time today, then I will tell you that we have done 6 Steamboat episodes so far. And if you want to enjoy these 6 episodes, if you want to get a lift, then do visit our HBCAC Steamboat YouTube channel or our Steamboat website. So I'm not ready to play any Taksiri, but have you ever thought about how we can hear our voice or how do we create our voice? So our 7th episode today, in this, we will understand Dhani, what we will see. So we have a pair of us, Pankaj Tarakey, who is connected to the HBCAC, Vigyan Patiba Project, and he works on science and maths, maths education. So without much delay, I invite Pankaj to start today's episode. Over to you, Pankaj. Yes, thank you. Thank you, Surabhi. And thank you so much for the introduction. So first of all, I will share my slides. I hope you can see these slides. Yes, Pankaj. I can see them. And let me tell you, if you have any suggestions or questions, please post them in the chat box so that our episodes are interactive. Okay, Pankaj. You can start. Okay. So first of all, good morning to all of you. And as of today is Sunday, the day of the Steamboat Session, I used to sleep very well in the morning. But do you know what happened? I used to sleep and suddenly I heard a voice that woke me up. Do you know what that voice was? I think you all must have fallen asleep because of that voice. So that voice was from my alarm clock. The alarm clock that I set in my mobile was that voice and my sleep woke up from that. And I forgot to set the alarm clock on Sunday. So because of that, my Sunday sleep got a little bad. But anyway, I had to come to the Steamboat Session, so it was good that I woke up. But just like that, maybe from you too, the day starts with some kind of voice or some kind of smell. And even during the day, when we go to school or go to the office or even when we are at home, we hear a lot of different kinds of smells around us. So can you give us some examples or can you tell us some examples that we hear in our daily work? Or do we not even notice the sounds around us? So can you tell us some examples that we hear in our daily work? Can you tell us in the comments on YouTube what smells or smells around us? Or can you tell us in the chat box if there is any connection to the Zoom? In the chat box you can see the sounds of birds. Local train. And there are some examples that you can hear. The sound of the fan. Right. And actually right now where I am in the room, maybe you can hear the sound of the fan. So correct. There is another comment that there is a sound of the water tap. So when the water tap falls in the water or when the water flows from the tap, it is the sound. I think so. So there are many examples where we don't even notice the sounds or smells around us. So we have seen some examples. And many times it happens that we hear some smells. So maybe we feel that we are suffering from this smell or we are hearing a lot of sounds in our ears. So first of all when we talk about the smell, then what is the smell? Do you want to know what is the smell? Survi, if I am changing the slides, do you want to see the slides? No, I don't see the slides changing. This is the first slide. So I will try this again. Now maybe you can see the slides. So I had a question from you. We started this session with how we hear many kinds of smells around us. Our day starts with many kinds of smells. So the main question that comes to our mind is what is the smell? So do you want to know what is the smell? One person has written on the chat that the vibrations in the air are very sound. Okay. And are there any other responses? One has written that sound is a form of energy that is produced due to the vibrations in the objects. So as we have seen these two responses, there are two important things that they have told us that sound is a form of energy or a kind of energy that we hear through the vibrations in our ears. Or the air molecules are vibrating back and forth like this. Because of which when the vibrations reach our ears, the sound is heard or the smell is heard. And we have seen this kind of diagram in our 8th or 7th textbooks. So when we read the sound wave or the smell in textbooks, we see this kind of diagram. And here you can see that some of the air molecules are very close to each other. And there is one region where the air molecules are very far away from each other. So when we have something or vibrations, when the air molecules are vibrating back and forth, this kind of pattern is formed in the air. Or in the air molecules, this kind of pattern is formed. Which we hear through the smell or the smell in our ears. And actually if we look at the textbooks of our 9th or 7th textbooks, then the sound wave or the smell in the air is shown in this way. This kind of picture is also shown where the smell is shown like a wave. Or it is shown as a wave that is going down. And here actually. A person is asking that because the air molecules are not present in the vacuum, so maybe we didn't hear the sound there. Correct, correct. So this is also an important point that they have also mentioned. The smell of the air or the smell that we hear or the smell to travel from one region to another or to try to travel, between those two points or between those two places, the smell of the air is very important. Because as we said, the smell is nothing. The smell is simply a vibration of air molecules. Because of that, we hear the sound wave. So if the air molecules are not present, then we don't hear the smell. So this was the point that if there is a vacuum, even if there is no air in the vacuum, then if we play a bell there, or if we want to talk to each other, then we won't be able to hear it. So this was also a point that was correct. So as I was saying, in our Class 7-8 textbooks, this kind of picture is also shown for the sound wave. And here, the sound wave is the air molecules of the air that are behind, or we call them oscillations. They depict oscillations. So this sound wave is oscillations. That is, how much the molecules of the air are behind their positions. It is shown here in this diagram. So we saw that the sound wave, which we saw in the last diagram, is behind the air molecules of the air. That is the actual longitudinal wave. We are representing it in a different way here. Where the down-down wave is behind the air molecules of the air, we are getting to know from here. And when we talk about the sound wave, along with the sound wave, we also have two properties that we often talk about when it comes to the sound wave. The frequency of the sound and the amplitude of the sound. That is, the amplitude of the sound, which is called avrutti and the amplitude of the sound, which we also call iam. It is important to talk about two things. When we talk about the sound wave, can any of you know what is the frequency and amplitude? Or can you also know what is the frequency of the sound wave and what is the amplitude of the frequency and what is the amplitude of the sound? You can also know this. Have you seen anything on YouTube? Ravi, I don't know. Actually, yes, sorry Ravi. So Pankaj, from amplitude, basically, the less and the more the sound we hear, we feel that. And the frequency, if the wave is oscillating in a second, it represents it. So, from high pitch and low pitch sound, we have the frequency. Okay. So, like Ravi told us something interesting here. When we hear sounds or any sound, the amplitude of the sound, whether it is low or high, we say its amplitude or its volume. When we talk about the sound wave, in terms of the sound wave, the amplitude of the sound wave or its volume, we can also talk about the sound wave in the form of the sound wave. If I am talking in a slow voice, you can say that my voice is less than the sound wave. If someone is shouting or talking in a high voice, we can say that his voice is Tivr. So, the amplitude of the sound wave, we can combine it with Tivrata. Similarly, as Ravi said, it doesn't have the same frequency. So, how many times the turns of the sound or the low tone is formed. If we try to mix the low tone with the high tone, how many times they are mixed. So, we call it a frequency. Actually, what I have told you I am not sure if it is difficult for you to understand, so as soon as we have seen the topic of the session, so next what we will do is that we will see the frequency and the amplitude, how it actually looks or what changes in the wave or in the direction of the amplitude, we will see that. Now I will show you a software or a website where we can see the frequency and amplitude. When you open the website, amplitude is the volume in layman's language and the frequency is pitch. Actually, I think many of us, when we go to learn music or maybe some of us sing songs, in the language of singing, the pitch word is used a lot. So when a singer says that he will sing in the high pitch or in the low pitch, in terms of physics, he wants to say that he will sing in the higher frequency. So I will share this now. You can see a wave on this screen, right? I have shared the screen. But it is not moving, right? No, it is not moving. So what I have done is that there is a website where you can see your sound waves here. So here you can see a very regular wave on the screen. I have opened this app and it is called Virtual Oscilloscope. What is oscilloscope? Oscilloscope is our sound waves. We can see the sound waves on the screen. We can see that the audio signal or the sound wave converts it electrically and digitally. We can see the sound waves on the screen. So here you can see a very regular wave pattern on the screen. You can also change the frequency from here. So here I am changing the frequency. You can see the frequency here on the right side. It is showing 1000 hertz. The hertz is the frequency unit. In a second, it is changing 1000 times. We can see a wave passing 1000 times in a second. Now it is 1000 hertz. If I reduce it, you can see what changes are happening here. Can anyone tell us what changes are happening here? Its width has increased. The same unit that was taking less space on X axis. Now it can change the number again. If it is 550, I increase it. Can you tell us what is happening here? Its length has increased. At least I think so. So when I am at 850 hertz, when we call a wave length as a cycle or wave length, we can see a wave length in this distance. When I reduce it, you can see the wave length is increasing. In a second, there are 601 waves. If I reduce it, there are only 344 waves in a second. So when we change the frequency, what happens here is that the air molecules of the wave are moving forward so fast or moving forward so fast that we can see through the frequency. When we increase the frequency, the molecules of the wave are moving very fast. When we reduce the frequency, it means that in a second, they are moving forward 521 times. The oscilloscope is showing us the motion of the air or the frequency on the screen. If you look here, if I change the oscilloscope gain, what changes are you seeing here? Highting. I am a little confused. Your voice was cutting in between. But I think I have heard that you are saying that the height of the wave is decreasing. You said that the amplitude is also decreasing. Yes, you are right. There is a difference in height, whether you are increasing or removing the gain. You are right. If I slide the gain knob back and forth, the amplitude of the sound wave means that the air molecule of the air is moving forward from the main position. We can see from the height of the wave. We can see from the height of the wave that the air molecule is moving back and forth. We used the oscilloscope to see how we can see the frequency and amplitude on the oscilloscope. We can actually see the changes on the frequency and amplitude on the oscilloscope. What changes are there in the sound wave? There is another option here where we can see the live sound on the oscilloscope. As I am talking to you here, you can see that the oscilloscope is showing me the waves. As I am saying, the frequency of the wave is changing or when I stop talking, the frequency of the wave is decreasing. Similarly, the use of the oscilloscope and the sound we talked about can be seen on the oscilloscope. This is a good device where we can also see the sound. We can also see the difference between the different sounds that we can see here. This was a virtual oscilloscope that I wanted to share with you. I will come to my presentation. We saw this virtual oscilloscope and how we can see the sound on the oscilloscope. We also saw the frequency and amplitude changes. We can see how the oscilloscope changes on the oscilloscope. I have shown you some of the sounds that we can see on the oscilloscope. I have shown you some of the examples on the oscilloscope. You can freeze the wave from the freeze input option. You can also freeze the wave. You can also take a screenshot of the sound you want to see. You can also try that option. I recorded these three sounds and you can see how they look. You can record some of the sounds and you can see how they look. As we saw on the oscilloscope we saw the frequency and amplitude changes. We saw it visually. We saw it visually. We also saw some of the musical instruments that we can hear on the oscilloscope. For example, guitar. We can hear the guitar when we plug the string. We vibrate the string through the air and we can hear it through the air. Similarly, we blow air through the air and then we vibrate the air through the air. We can hear the air through the air. Similarly, when we play guitar or harmonium we press a key. If we press a key, there is a hammer inside the harmonium. You can see here these white hammers. They hit the string with a string. They vibrate the string and we can hear the air through the air. I am talking to you and you can hear my voice and your earphones vibrate. You can hear my voice and your phone's speakers vibrate. My question is when I am talking to you I can hear the sound from my mouth. You can hear the sounds from your mouth. You can see here the sound comes from the mouth and the sound comes from the mouth on top. You can hear the sound from the mouth on top. We make it. What is our body part? Or from where do we get our voice? How do we get our voice heard? Can anyone know? Or should anyone tell? One person writes that it is a voice box. The voice box is produced by the voice. He has written it for a year and nothing else. So this is the answer. And if there is something else on YouTube, then... Okay. Yes, so... Exactly. So this is written as a vocal cord. Yes, so this... I think the first answer was that larynx and... Now you have told me about the vocal cord. So actually this is a correct answer. And the second one is that we hear it from the ear. That is also correct. And... Correct. So when we say that a voice comes out of our throat, then in our throat as well, with which the voice is generated, we call it larynx. And larynx is in the upper part of our throat. And in larynx as well, the vocal cords vibrate. And because of the vibrations of the vocal cords, we get our voice out of our mouth. And if we want to make a sound while singing, then we can make a sound while singing. So... There is a larynx in our throat. And there is a vocal cord in the larynx as well. You are able to see these two vocal cords. So these two vocal cords vibrate and create a sound from our throat. Or make a sound. And similarly, when we make a sound, we get our voice out of our throat. So we get our voice out of our throat. Through our ears. But in our ears as well, actually, if we look at it, we must have seen speakers as well. Speakers... Speakers also... There is something like a black cloth on a speaker. When that sound signal comes in the speakers, then the cloth vibrates or the cloth moves. Similarly, in our ears as well, this tympanic membrane or we call it the head of the ears. So the head of the ears vibrates and the vibrations of the head of the ears then go into the inner part of the head of the ears. You can see these golden cockles or we can see something like a snail. It's called cockles. Actually, all our vibrations are sent through the electrical signals through the cockles of the nerves. So the sound waves in our ears in the inner part, in the cockles, through the neurons, that is our brain... Sorry, not neurons, our signals go through the nerves of the ears to our brain. So that way, we can recognize that sound. We get to know where this sound came from. So here we saw that we are humans. How humans make sounds and how we can hear them. So as we saw in the previous slides that we talked about some musical instruments. And if you... I think many of us must have heard some musical instruments. And I think when we play some musical instruments or listen to them, we can easily tell that the sound we heard is played by these instruments. So we will talk at this point that if we have two instruments and we hear those two sounds, our brain or through our ears our brain can tell us that these two sounds were heard by two different instruments. So... If... If these two instruments... the same frequency and same amplitude, like we talked about the frequency and amplitude, if these two instruments have the same frequency and the same amplitude or generate the same amplitude of the sound, then will we hear the same sound? This is my question to you. If these two instruments on the left side are called trumpets and on the right side are called flutes, then if these two instruments have the same amplitude and the same frequency to generate the same frequency, then will they hear the same sound of my ears? Can I tell them that they will hear the same sound? Disha wrote it or not? And one more person wrote it? Yes. Okay. So actually, I will share another website with you. They have tried to play the same sound on the same frequency and the same amplitude in the same frequency. But let's see how they will see it or what happened in that case. So I will share it again. You can see it on the screen. Yes. So actually, they have done the same frequency and the same amplitude of the trumpet and the flute. They have tried to play the same frequency and the same amplitude. So let's see how they saw the play. So first of all, let me tell you what this part is showing on the screen. So what you can see below is the frequency. This is a graph where the numbers below are the frequency, the frequency of the trumpet. We will see something on the X axis. I will tell you what it is. So first of all, I play the sound of the trumpet that they played. So you can observe what you can see. Didn't you hear the sound? Yes, I did. Will you play it again? Yes, I was hearing the sound because I didn't hear it. No, I didn't hear it. I think the others did too. I have heard it for the second time. Okay. So I will play it again as soon as the sound is gone. So I will play it twice. And you can observe how it is showing. I will play the sound of the flute. They have also tried to play the same frequency and the same amplitude. So this is the sound of the flute. So is there any difference between the two of you or would you like to tell us what we were seeing here? We have heard both the sounds from both the instruments. But when we were looking here, did you see any difference or would you like to tell us? Aditi, in the first one, I think in the trumpet one, there were a lot of peaks compared to the first one. Yes. The peaks in the flute were quite low and in the trumpet there were a lot of peaks. And actually, I actually played these two instruments. Yes. The pitch of the instruments were different. The pitch of the instruments were different. Okay. So if we closely observe the sound that is playing then it will end soon. So I have taken a screenshot of it. I will share it with you. So as you can see here, when I play the sound it is 439 or 439 Hz. You can see a peak there. The peak is a little bit taller than the rest of the peaks. Now I am going to tell you that when I said on the Y axis it will show us the amplitude and the amplitude. So when I play the trumpet you can see on the 439 Hz we have the tallest peak and on that frequency we have the most amplitude. Can you see here? The peak of the 9 Hz was the tallest peak here. And when I play the flute in the flute you can see that there is a peak on the 439 Hz which is the tallest peak. So here we can see that the pitch played the same from both the instruments. I tried to play the 439 Hz but when those two frequencies were trying to play the same here they can see that only those two frequencies are not playing. So in the case of the trumpet along with the 439 Hz we can see the additional frequencies along with it. And when we listen to it we can only hear the frequency of the 439 Hz played but along with it the other frequencies are also mixed like this the same flute when they tried to play the frequency of the 439 Hz along with it the additional frequencies were also mixed and generated. So what we were seeing in the graph where the frequencies were on the X axis and on the Y axis we were seeing the amplitude of the sound and we also called it a spectrogram. So what is happening in the spectrogram is that when we try to play a sound with any instrument or play a sound generally we feel that we are only trying to generate a single frequency or we are hearing the same frequency but in actual along with that one frequency some additional frequencies are also mixed Pankaj the sound played by the trumpet the same frequency the same amplitude but when we are listening we feel that the trumpet sound is a little slow we are feeling that because the waves we saw in the flute along with that the additional frequencies are very few or some limited number of frequencies which are mixed with the sound and we are hearing the trumpet all these frequencies which are our main frequency with 439 Hz and their amplitude their peaks are relatively tall and we are hearing the sound so the lower part we were able to see that we are creating a sound with our instruments and we are trying to play the sound so in that one sound or in that one sound there are many different frequencies and what we are seeing here we call it a spectrogram so this spectrogram what it does is when we hear a sound then if there are many different frequencies then there will be a mixture or there will be a lot of frequencies there will be a lot of frequencies so this spectrogram it shows us the amplitude of those frequencies that there was a particular frequency and the other the additional frequencies were the amplitude or the volume here I think this is a question of Disha what would you like to say because the first part is not clear it says is this the same thing happening with humans as well and is that the reason why we can identify people just with their voices like we call our mom and dad or friends without looking at their faces or who is talking on the phone so is that the same thing happening like in flute and other musical instruments that the same frequency still we can distinguish actually so we have tried to play one note with both instruments but there are some different combinations of frequencies that separate the sounds so the pattern of the sounds is also based on the instrument so like and this is the quality of the sound with the main frequency some additional frequencies are also connected we call them quality of sound or timbre in English so we call it the quality of the sound which we can easily tell that this particular sound is of this instrument and when we play a flute we can easily tell that this sound is of the flute and the quality of the sound depends on the instrument so and actually the quality of the sound is applicable for the voices of our humans that is our voices also have different sound waves or different combinations of frequencies so we can tell each other so now actually we will stop so when we saw on the spectrogram the sound that came out of the instrument the main frequency the port 39 hertz along with that there were some additional frequencies and those additional frequencies were different in the case of trumpet and their amplitude was different and in the case of flute there were some different frequencies and their amplitude was less because of which we were able to tell those two different sounds or we were able to tell those two different sounds but and the characteristics of the sound we call it timbre or we call it guñata in Hindi so when I was talking and we also saw on the oscilloscope that the oscilloscope also shows us some waveforms some waveforms we were able to see on the oscilloscope but the ones below the peaks we were showing we easily or we are able to see that when we say that there was a single frequency sound actually it was not just one sound there were additional frequencies which were mixed and we were able to hear a single sound so in the terms of music it is also called timbre and this is the quality that is judged so like a cow a cow or a cow so when they sing their sounds are also analysed on the spectrogram and then to improve their voice they see from here some frequencies in their voice they feel that they are not hearing well so from here they get to know so in the music industries when digitally sound recordings generate music this is used a lot from where the concept of sound quality is used so we just saw that any musical instrument each instrument has a different sound quality so after that we will make our own musical instrument so the musical instrument that we are going to make before that we want to know for example there is a harmonium so you can see that the pattern of the keys is repeated here there are 7 white keys and the 5 black keys the pattern is repeated and if the 7 white keys of the harmonium if we play only white keys then we will hear all the sounds we can hear so if we start with the first white keys we will play only white keys so we will hear all the sounds so this sound actually how the mathematics relation is the frequency we will set anything or you can imagine the frequency is like 800 hertz so if we multiply the rate then the frequency of the rate will be 900 hertz similarly we can set the frequency of the song we will multiply the frequency of the music we will multiply the frequency so we will get the frequency of death so now we will use our musical instrument which we will make we will try to play all the sounds and the musical instrument we are making is Jaltarang I think many of us have seen how they make Jaltarang and how the various artists make Jaltarang make Jaltarang and play it so we will also try to make Jaltarang so what we will do to make Jaltarang any utensil cup or glass we will use cup or glass we will use it and what is Jaltarang in Jaltarang the artist who is a katori or glass he hits the glass with a wood or he hits it with a wood which makes Jaltarang so here I have I have a beaker and this is a cup so when I hit this cup when I when I hit this beaker you can hear the sound you can hear and if I hit this cup so you can hear the difference yes one is more the voice is shrill and the other is more dull the cup is dull right so when I hit this cup the voice is more in the ears it doesn't sound and when I hit this beaker I can hear the voice so if I take the instruments or what is the difference between the cup and the beaker or can you tell what is the difference in the sound which I understand and there are two types of writing that the material which is made is of a glass I don't know plastic or ceramic this is ceramic and does it matter whether it is thin or thin or does it matter yes so if this cup is quite thick it is quite thick so maybe because of that the sound is generated or the sound we can hear so because of such things you feel the sound or the frequency will have the effect on it like the material was different one was glass and one was ceramic so because of that we could hear different frequencies so there are many other things which can be heard in the frequency so you have to think about this point and when you make it you can notice that because of different things we can hear the frequency and this is done after that when we make the water in the water we have to hear all these or we have to play all these so we have to measure the frequency so to measure the frequency we have to in our computer or in our computer we have to measure the frequency for example we have Rdino journey virtual oscilloscope we have to measure the frequency on that or any other app there are many apps where we can measure the frequency so we will use any app to measure the frequency and first of all all the instruments i.e. cup or glass we will play them and we will note the frequency of the frequency and then in the water we see we use water to adjust the frequency so first of all we will empty it and we will play it and measure its frequency then what we will do next we will add all the water after adding all the water we will measure its frequency we will get the beaker or any glass we will get a frequency range similarly we will use other glasses or bowls similarly when it will be empty we will measure its frequency and when it will be full we will measure its frequency then then we will get 7 bowls or 7 glasses to play so the lowest frequency which we will get we will set its frequency so if this bowl and compared to other bowls its frequency is lowest so I will fix it with 7 frequency and then after 7 we will get the rate so we saw if we multiply its frequency 9 by 8 then we will get the rate frequency so we will calculate the frequency and then we will use the next glass we will try to adjust the frequency by reducing the water so I have made these adjustments and I have made a waterfall so I will show the waterfall the camera can you see the waterfall you still have screen share are you saying that are you showing in the video I think you will have to share the screen now you might be seeing yes so as I said we will get 7 bowls to play so here I have a glass of wine and other beakers and the frequency of the glass was lowest so I thought I will use it for 7 and then I have set the rest of the beakers in the frequency adjust and you can see the level of water is different and the beaker I have used is a different beaker because if I was using the same beaker I was not getting the frequency so I used the smaller beaker whose frequency I was getting the frequency needed so now I will play 7 soup let's see if it is tuned properly are you hearing this yes can speakers go closer to hear more can you stop the screen share so that the part of the beaker can be seen in the spotlight thank you so I will play the voice is not coming okay it was coming wait I will close the mic can you hear the voice yes this is perfect okay I have set the frequency on the snake snake snake snake snake snake yes I heard it so you make my question the empty glass with the lowest frequency I can set it on the snake right after that I fill the water with empty glass how do I do it second beaker put water in it measure the height of the water and then multiply with the ratio is it coming or not in software yes in software I measured the frequency and actually these beakers were available individually like I said when the beaker was empty what was the frequency when the beaker was empty what was the frequency I noted down after that when I set the frequency of the empty glass after that the next frequency I was getting something by multiplying 9 by 8 so I saw the frequency range of the glass I was getting so what I did the height of the water or how much water changes in the frequency I noted down then a certain amount of water or a certain amount of water after reaching that frequency was playing on it similarly then I adjusted the next frequency this beaker was coming in that range that frequency range then I adjusted the level of the water then at a certain point I was hearing that frequency so similarly while continuing the next frequency I fixed the beaker yes so here you can see I was starting with this with a clean frequency and then from there I set the frequency until the end and then again the next sound this sound has a double frequency so I did not do that but I was not getting the beaker so I did this much and actually you can see when I was going from M to perk frequency the beaker I was not getting the frequency range okay perk frequency was a certain frequency and and these beakers their range was less than perk frequency so perk frequency I was not going to get this beaker so that's why I had to use these beakers and you can see from here when I go to these beakers there are many changes you have something what this beaker this beaker and then this perk the beaker when I was going from perk frequency so from this beaker I was not getting the frequency so I had to use a different beaker okay so here you can see the material here is the same but still I am getting a different frequency so here what is the difference from which I am getting a different frequency from here maybe because the height of the beakers and the height of the water right correct so here the height of the water in the beaker the height of the beaker is different the weight of both of them will also be different so all these things will affect the frequency okay so this is done so whatever the beakers are connected with us I would request that also try to make this water-based and actually when I was seeing this and an interesting wine glass I saw an interesting wine glass now if I add water in the wine glass and if I do this with my fingers when I turn it it will sound this is a little difficult but I think it took some practice you starting in rotation it is still not but a little sound see can you hear this sound yes yes so what is the speciality of wine glass in any glass material for now when I saw particularly with wine glass I have seen normally with glasses I tried but there was no sound so you can also think what is happening here and I also think or I also try not to we have left this question for the audience yes so I think we have crossed 12-20 your this my screen share will you change the video yes we can change the video will you share the screen again or ok thank you almost 12-20 just a small question which you took for ratios what are the fixed ratios what are the calculations actually there is a quite interesting mathematics ok there is not much detail because we have time these are our keyboard instruments we are getting more volume I guess these are our harmonium or piano like keyboard instruments their tuning when we play any key keys are tuned at a certain frequency so the tuning of mathematics certain sounds if we play two sounds together those two sounds our ears one is very soft both sounds play together or less soft or a bit harsh so when we analyze when we listen and we like to listen we see the frequency ratio between those two sounds was a simple ratio ok so we have heard their Swords these are also their ratios with respect to the frequency of Sa these are the frequencies in terms of simple ratios like after Sa there are 9 by 8 times Sa similarly the piano or harmonium the frequency set all the keys are related to simple ratios or their tuning is mathematically related to each other ok then thank you Pankaj what else I was saying the tuning of the piano or the harmonium has a very interesting mathematics for now if we don't have time then we can't discuss ok thank you so much for joining us and you gave us a lot of information and how to make it and if there are any questions then you can write on our e-mail and tell you that next month we will bring you a new episode on 12th June and that session will be live and we hope that you enjoyed thank you so much everybody thank you Pankaj so bye then should we end here I would also like to thank all the steamboats