so hello and welcome to this lesson in this lesson I'm going to look at the vernier scale we want to understand the idea of the list count the vernier calipers has basically two scales it's got a main scale which is this one here the upper scale is referred to as the main scale and it's got this lower scale here which slides along the main scale I'll be able to show you in the next lesson how this scale slides and itself are - as the vernier calipers rather itself are - as the vernier scale let's briefly look at the main scale the main scale is just like the scale you have on the meter rule the mid rule is graduated in centimeters and millimeters so from here all the way to that point is a length of 1 centimeter that 1 centimeter is divided into 10 equal divisions and one division you know very well that it equals one millimeter in meters one millimeter is the same as 0.1 of a centimeter I just need to divide the one millimeter by 10 - to convert it into centimeters alternatively I can take this one centimeter divided by 10 divisions and I will find that one division is 0.1 centimeter so on a meter rule we count in terms of 0.1 centimeter for example starting from 0 from here to here is 0.1 centimeter then I'll add another 0.1 centimeter to get the distance from here to here being equal to 0.2 centimeters similarly I'll add another 0.1 on to this one to get is 0.3 to get the distance from here to here being equal to zero point three centimeters and so on until I get one centimeter what I want you to see is that I'm moving in steps of 0.1 centimeter in other words I'm counting in terms of 0.1 centimeter and this is the smallest division that I have on a meter so we can comfortably say that the list count on a meter is 0.1 centimeter now is it possible to divide that 0.1 centimeter into ten equal divisions and these divisions should be visible to the naked eye that is very difficult it's not possible to to see it if I divide this by a further ten so that I can get 0.01 centimeter it will not be able to see it will not be visible and therefore it cannot be read accurately that is why we need to introduce the idea of the vernier scale first of all let us look at the vernier scale the vernier scale over here has starts from zero and it is got ten divisions and these ten divisions occupy a distance equal to from here to here on the main scale what is the distance from zero all the way to this 90 division here you will agree with me that this is zero point nine centimeters so zero point nine centimeters is from here all the way to there and then there are ten divisions in that distance of zero point nine centimeters there are 10 divisions I've named them in fact look at the spaces 1 2 3 4 5 6 7 8 9 10 10 divisions in a distance of zero point nine centimeters so the question we want to ask ourselves what is the length of this division here or that small distance how do I get it I need to divide zero point nine centimeters by ten divisions and I will get zero point zero nine centimeters so the length of 1 division on the vernier scale is zero point nine zero nine centimeters but the length of 1 division on the main scale you were able to see that it was zero point one you can either add another zero there because you want to compare this is zero point zero nine centimeters so you can obviously see that the length of 1 division is smaller the length of 1 division on the vernier scale is smaller than the length of 1 division on the main scale what is the difference between them in other words what is the size of this distance here this one here we can get a distance by subtracting 0.09 from 0.1 so if I do that 0.1 minus 0.09 I get 0.01 centimeters that short distance that very slight distance there has a length of 0.01 centimeters this distance here is referred to as the least count of a Vanya calipers the least count of a vernier calipers remember what is what is the meaning of the least count for the meter rule we count in terms of 0.1 0.1 0.1 0.1 so if you told that the least count for a Vanya calipers is 0.01 we will count in terms of 0.01 for example we'll start from 0.01 centimeters the next one will be 0.02 the next one will be 0.03 the next one will be 0.04 until we get zero point one zero centimeters in other words we've got from here all the way to here let's say this is 0 and this is one millimeter or 0.1 of a centimeter we are subdividing this one millimeter into 10 equal divisions 1 2 3 4 5 6 7 8 9 let me add another one there to make it 10 in other words this distance here is the one which we are calling 0.01 centimeters very very small here I have magnified the scale remember if you look at a meter rule or a normal 30 centimeter ruler this 1 millimeter is a very small distance so I wanted to imagine dividing that very small distance by 10 equal divisions you will hardly be able to see those divisions but the vernier calipers helps us to read up to this value up to this level of precision that's a new term that I've mentioned I will be explaining what it means but for now we can say that the vernier calipers is a more precise measuring instruments compared to the meter so in terms of precision the vernier calipers is more precise so let's review the main points of this lesson number one we wanted to make it clear that a vernier scale or a vernier calipers has two scales the main scale and the vernier scale the main scale is graduated the way a meter rule is graduated and it's got the value of the least count being zero point one centimeters the vernier scale is also also has 10 divisions and the length of 1 division on the vernier scale is 0.09 centimeters and it is therefore smaller than the length of 1 division on the main scale and the difference between the length of 1 division on the main scale and the length of 1 division on the vernier scale is 0.01 centimeters this value is referred to as the least count and that means that we count in terms of 0.01 of a centimeter on a vernier scale so the vernier scale helps us to read values to the second decimal of a centimeter accurately that is not possible with the meter or the meter rule helps us to read up to 0.1 of a centimeter accurately but the vernier calipers goes to the next decimal so this is what I'd like you to do I want you to go through the video once again because in the next video I'm going to teach you how to read the vernier scale this is an announcement for students we are in the process of putting together video lessons for formal inform to infantry inform fall that is for the Kenya April 4 system of education this is an online class where lessons are organized in line with the system of education you will be able to access support material such as notes and practice questions all you need to do is send me your email and I'll send you the link to the class please specify the form that you're interested in so that I can send you the correct link send your email address - montreux kagwe @ gmail.com take advantage of the offer while it is free