 channel for physics. Please subscribe my channel. Hello and welcome back to another episode of physics partner. Today I am going to discuss with you about the micrometer is also called screw gauge and some people's pronouns screw gauge. So the micrometer screw gauge is actually a device which is used to major the diameter of very small objects like a sphere or even a wire. It is used in industries to major. Nowadays there are more advanced micrometers are available which are digital and this micrometer is also used in education purpose also. It's a part of a physics curriculum. That's why we are going to study this today. So let's explore more about micrometers. So micrometer has two scales. One is called main scale. You can see over there this 0 5 10. This scale is considered as main scale whereas another scale is there which is called a circular scale. Right now you can see all readings are 0. So there is a purple blue and red readings. So let us understand how can we use the micrometer to major some radius. Okay let's explore more about micrometer. So if I start opening the micrometer you can see that some readings are going to be changed. So let us explain something about these readings. So there are three types of reading you can see here. Number one is a purple one which is main scale reading. It's very simple count one two three four and five. So the main scale reading on this micrometer is five whereas the circular reading you can see here is 0.21 because it is in millimeters so I'm taking as 0.21. Now let's see here also why it is 0.5 the blue color. Actually it is in between the next line. You can see after 5 and 6 it is in between. If I increase more little so for example I'm going to increase a little and now it's 6. So when it's completely 6 you can see there is no more blue reading is here. It means it is exactly on a main scale point either is 6 or 5. So if it is in between 5 and 6 it becomes 0.5 like before. So here it is now 0.37 0.5 and 5. So we have to note down three readings main scale reading circular scale reading and the and the subdivision. We have to add them and we can get the final answer. So right now what is opening is 5.87 millimeter. So that is the reading of this micrometer. Let's more understand about it. The circular scale when it's take a complete rotation it is it is called a pitch. Pitch means it's make a complete one revolution one complete round as considered as pitch. The least count of this device is 0.01 millimeter. What do you mean by least count? Least count means minimum it can measure 0.01 millimeter which is a very very small measurement. So that is called a least count. To understand least count let's take an example of a clock. In the clock you can minimum measure one second. So the least count of the clock will be one second. So let us take a metal nut and try to measure it. There are so many sizes available. Let's try one by one and see the readings. So if I select this one the reading is showing it's 2.87 millimeter. You can see again you can little explore it. You see the second line which is the purple one is the second major line on main scale and 0.37 wife 35 36 37 as I told you it's millimeter 0.37 is the circular reading and because the blue line is not exactly on it. So it is a 0.5. Let's try the next one. Next one will give exactly line here as exactly five. So it is five and 0.46. Similarly try more. You can see here so and so on. It is usually used in industries but not only industries it is also used for educational purpose. So it has also included in so many international curriculum. Let's see where we are using micrometer in our daily life. So micrometer is used in industries for measuring different kind of instruments which are very small especially the diameters you can take and you can find the radiance by calculation. It is used in laboratories for a small measurement. It is also used in schools for educational purposes. So that's a small video. I hope you enjoyed the video. It's very simple. Micrometer is also called a screw gauge is a device which is used to measure the diameter of small parts and usually it is used in industries. So thank you very much for your listening. Take care of yourself. See you in the next video. Goodbye.