This number is the multiplier. i really appreciate your help. You can measure the actual value of a specific resistor using a device called a multimeter. Some of the characteristics of a potentiometer are:eval(ez_write_tag([[300,250],'circuitstoday_com-large-mobile-banner-1','ezslot_21',115,'0','0'])); Since, we also need to know the taper of the pot, the manufacturers use marking codes for indicating the taper of the pot as well. Figure 1 shows some practical pots, while figure 2 shows the standard symbol of the same. When connected to a circuit, the two fixed terminals are connected to the ends of the resistive elements while the third terminal is connected to the wiper.eval(ez_write_tag([[580,400],'circuitstoday_com-box-4','ezslot_17',110,'0','0'])); In the circuit diagram shown  below,  the terminals of the potentiometer are marked 1, 2 and 3. The following figure shows you two more examples of resistors and their values. This number is the first digit of the resistance. If you have a precision (five-band) resistor (which you’re unlikely to use for projects in Electronics For Kids For Dummies), the third band gives you the third digit of the resistance and the fourth band gives you the multiplier. In the resistor shown in the preceding figure, the first band is yellow, so the first digit is 4. Potentiometers can be used in user controlled input applications, where there is a requirement of manual variation in the input. Standard resistors have four color bands. Its resistance is approximately zero and it is used to connect two traces on a printed circuit board (PCB). Higher the length, higher is the resistance, provided the material of the resistor and its cross-sectional area remains same. The working principle can be made clearer, by solving the example below. I have published following article in Electronics Design Versatile Multistep Resistor Load Bank is Simple and Modular It is a unique topology and can be used to teach series parallel connections of resistors. If you can’t determine which is the first band, look at the two outer bands. Most standard resistors have tolerances of 5%, 10%, or 20%, and most precision resistors have tolerances of 1% or 2%. The fifth band tells you the tolerance. In the resistor shown in the preceding figure, the two-digit number is 47 and the multiplier is 10, so the nominal value is. RA is in series with R7 therefore the total resistance will be RA + R7 = 4 + 8 = 12Ω as shown. ThanK YoU for you great help Look up the color of the third band in the column labeled “X” and find the number associated with that color. The color, gold, in the column labeled “tolerance” in the figure represents a tolerance of 5 percent. They are kept fixed for most of the time. Resistors can be connected together in an unlimited number of series and parallel combinations to form complex resistive circuits. How to Build a Simple Photoresistor Circuit. So, if you buy a 100 Omega precision resistor, chances are its actual value is within 1 or 2 of 100 Omega. Web Editor . Also during the calibrations of a device, a preset pot are often mounted on the circuit board. Thnkyou so much…..It was a life saving thing…..really! Thank you for your answer. Look up the color of the second band in the column labeled “2nd digit” and find the number associated with that color. The fourth band tells you the tolerance of the resistor, which indicates how far off the nominal value the actual resistance could be. Now that the characteristics of the pot have been discussed lets have a look into what are the types of potentiometers. We and our partners share information on your use of this website to help improve your experience. Then the complex combinational resistive network above comprising of ten individual resistors connected together in series and parallel combinations can be replaced with just one single equivalent resistance ( REQ ) of value 10Ω. You can count on the actual resistance of a precision resistor being really close to its nominal value. Now a closer look into the figure, we can see that at the current position of wiper, there are two resistive paths just like the resistor is split into two resistors. With this we have covered almost all the aspects so that now you know the basics of a potentiometer. eval(ez_write_tag([[300,250],'circuitstoday_com-medrectangle-4','ezslot_16',109,'0','0']));It is represented by a zigzag line with an arrow pointing inwards at the center. Starting from the right hand side and using the simplified equation for two parallel resistors, we can find the equivalent resistance of the R8 to R10 combination and call it RA. At first glance this may seem a difficult task, but if we look a little closer we can see that the two resistors, R2 and R3 are actually both connected together in a “SERIES” combination so we can add them together to produce an equivalent resistance the same as we did in the series resistor tutorial.