You can find out the cross-sectional area of the cable in several ways. The easiest is to look at it on the markings on the insulation. But sometimes this is impossible, because it is either absent or already very worn out. We have to use other methods.
Instructions
Step 1
Use available tools and measuring instruments. It is best to use a micrometer or vernier caliper to find out the size of the cable. These measuring devices are very rare to be found in a standard set of household tools, so you can try replacing them with a tape measure or ruler. It also does not hurt to remember the school geometry course. The area of the circle (the cross-section of the wire is exactly this geometric figure) is equal to the product of the number P, equal to 3, 14 (you will not need more than two decimal places in this case) and the square of the radius of the circle. To determine the radius, divide the wire diameter by 2. If you want to use the diameter for calculations, use the following formula S = 0.78D².
Step 2
Use a vernier caliper to measure the diameter of the wire. Then, to find out the cross-section of the wire, multiply the obtained diameter by it, and then by 0.78. The resulting value will be the cross-section of the cable.
Step 3
Use a ruler or tape measure, as well as a pencil, to determine the size of the cable. Wind the wire tightly around the pencil. The more turns are made, the more accurately the cable diameter will be determined. It is desirable that there are at least 10 turns. Then measure the distance from the beginning of the first turn to the end of the last one using a ruler or tape measure. Calculate the cable cross-section using the formula above.
Step 4
If the cable is stranded, multiply the result by the number of conductors to get the cross-sectional area. If the conductors have different diameters, measure each one separately, then use the above formula and add the obtained values to find out the total cable cross-sectional area.
