 In this video, we'll be looking at the factors that affect our conductor's resistance. Here we have a crew drawing, but a drawing nonetheless of a conductor. So we have a length, we've got a diameter here, and we have a type of conductor that we're dealing with. Those are generally the factors that affect our resistance. When we're calculating out the resistance of a conductor, we can use this formula. R is equal to K times L over CMA. R is the resistance. K works out to be the constant of the natural resistance or the resistivity of the wire, depending on what the medium is, whether it's aluminum or copper, would be the two most typical ones that we use. But you can also have brass, cadmium, copper, weld, iron, nichrome, silver, steel, tungsten. There's a bunch of them out there. So that's the constant, the resistivity constant. So that's your K. Length is going to be the length of the conductor in feet, and CMA is going to be the circular mill area of the conductor. So for our K, we're going to use either copper or aluminum. Those are our two most common types of conductors out there. For aluminum, that constant of resistivity is 17. For copper, it is 10.4. So as an example, say this conductor here was 800 feet long of number 16 AWG copper conductor. So we have the length. We have our K, because we know it's copper, so we'll be using 10.4. We don't have the CMA. So what we need to do for that is to go to our table. We go to our table here, and we see we've got our gauge number here. We go all the way down until 16. We move across here until we get to the area in circular mills, and it ends up being 2,583. So now we have everything we need. We know we have an 800 foot length. We have a number 16, which gives us a CMA of 2,583 CMA, and we know that our copper is 10.4 for resistivity. So we plug all the numbers that we know into the formula. 10.4 is our K, 800 is our L, and our CMA is 2,583. Multiply those two, divide it by that, and we get a resistance of 3.22 ohms for that length. So again, the factors that affect this are the resistivity, the length, and the CMA. All these are based on 20 degrees Celsius. In order to determine what your resistance is when you have a rise in temperature, you have to watch the next video on resistance and temperature.