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barcode generator in vb.net Capacitive Reactance and Frequency in Software
Capacitive Reactance and Frequency Code 3/9 Scanner In None Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications. Code 3 Of 9 Creation In None Using Barcode creator for Software Control to generate, create Code 3/9 image in Software applications. In one sense, capacitive reactance behaves like a reflection of inductive reactance. But looked at another way, X C is an extension of XL into negative values. If the frequency of an ac source (in hertz) is given as f, and the capacitance (in farads) is given as C, then the capacitive reactance in ohms, X C, is calculated as follows: X C = 1/(2 f C ) Again, we meet our friend ! And again, for most practical purposes, we can take 2 to be equal to 6.28. Thus, the preceding formula can be expressed like this: XC = 1/(6.28f C ) This same formula applies if the frequency, f, is in megahertz and the capacitance, C, is in microfarads. Capacitive reactance varies inversely with the frequency. This means that the function X C versus f appears as a curve when graphed, and this curve blows up as the frequency gets close to zero. Capacitive reactance also varies inversely with the actual value of capacitance, given a fixed frequency. Therefore, the function of X C versus C also appears as a curve that blows up as the capacitance approaches zero. The negative of X C is inversely proportional to frequency, and also to capacitance. Relative graphs of these functions are shown in Fig. 144. ANSI/AIM Code 39 Reader In None Using Barcode decoder for Software Control to read, scan read, scan image in Software applications. Paint Code 39 In C#.NET Using Barcode drawer for Visual Studio .NET Control to generate, create Code39 image in .NET framework applications. Problem 141 Suppose a capacitor has a value of 0.00100 F at a frequency of 1.00 MHz. What is the capacitive reactance Printing Code 39 Full ASCII In Visual Studio .NET Using Barcode generation for ASP.NET Control to generate, create Code 39 image in ASP.NET applications. USS Code 39 Generator In VS .NET Using Barcode maker for VS .NET Control to generate, create Code 39 Extended image in .NET applications. Capacitive Reactance and Frequency 217
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UCC128 Creation In None Using Barcode maker for Software Control to generate, create USS128 image in Software applications. Data Matrix ECC200 Creation In None Using Barcode encoder for Software Control to generate, create DataMatrix image in Software applications. is negatively, and inversely, proportional to capacitance. Capacitive reactance is also negatively, and inversely, proportional to frequency. Code 128A Generation In None Using Barcode encoder for Software Control to generate, create Code 128C image in Software applications. USS Code 39 Creation In None Using Barcode creation for Software Control to generate, create Code 39 Extended image in Software applications. Use the formula and plug in the numbers. You can do this directly, because the data is specified in microfarads (millionths) and in megahertz (millions): X C = 1/(6.28 1.0 0.00100) = 1/(0.00628) = 159 This is rounded to three significant figures, because all the data is given to that many digits. Uniform Symbology Specification Code 93 Creation In None Using Barcode creator for Software Control to generate, create USS 93 image in Software applications. Bar Code Scanner In Java Using Barcode decoder for Java Control to read, scan read, scan image in Java applications. Problem 142 What is the capacitive reactance of the preceding capacitor if the frequency decreases to zero (that is, if the voltage source is pure dc) In this case, if you plug the numbers into the formula, you get a zero denominator. Mathematicians will tell you that such a quantity is undefined. But we can say that the reactance is negative infinity for all practical purposes. Problem 143 Suppose a capacitor has a reactance of 100 at a frequency of 10.0 MHz. What is its capacitance In this problem, you need to put the numbers in the formula and solve for the unknown C. Begin with this equation: GS1  12 Scanner In None Using Barcode scanner for Software Control to read, scan read, scan image in Software applications. Barcode Decoder In Visual Studio .NET Using Barcode recognizer for .NET framework Control to read, scan read, scan image in VS .NET applications. 100 = 1/(6.28 10.0 C ) Dividing through by 100, you get: 1 = 1/(628 10.0 C ) Multiply each side of this by C, and you obtain C = 1/(628 10.0). This can be worked out with a calculator. You should find that C = 0.000159 to three significant figures. Because the frequency is given in megahertz, the capacitance comes out in microfarads. That means C = 0.000159 F. You can also say it is 159 pF. (Remember that 1 pF = 0.000001 F.) Paint Bar Code In ObjectiveC Using Barcode printer for iPad Control to generate, create bar code image in iPad applications. Bar Code Creation In Java Using Barcode generation for Java Control to generate, create bar code image in Java applications. 218 Capacitive Reactance
Printing Bar Code In VB.NET Using Barcode creation for .NET framework Control to generate, create bar code image in .NET framework applications. Create Bar Code In Java Using Barcode printer for BIRT reports Control to generate, create barcode image in BIRT reports applications. Points in the RC Plane
In a circuit containing resistance and capacitive reactance, the characteristics are twodimensional in a way that is analogous to the situation with the RL plane from the previous chapter. The resistance ray and the capacitivereactance ray can be placed end to end at right angles to make a quarter plane called the RC plane (Fig. 145). Resistance is plotted horizontally, with increasing values toward the right. Capacitive reactance is plotted downward, with increasingly negative values as you go down. The combinations of R and X C in this RC plane form impedances. You ll learn about impedance in greater detail in the next chapter. Each point on the RC plane corresponds to one and only one impedance. Conversely, each specific impedance coincides with one and only one point on the plane. Any impedance that consists of a resistance R and a capacitive reactance X C can be written in the form R + jX C. Remember that X C is always negative or zero. Because of this, engineers will often write R jX C instead. If an impedance is a pure resistance R with no reactance, then the complex impedance is R j 0 (or R + j 0; it doesn t matter if j is multiplied by 0!). If R = 3 with no reactance, you get an impedance of 3 j 0, which corresponds to the point (3,j 0) on the RC plane. If you have a pure capacitive reactance, say X C = 4 , then the complex impedance is 0 j 4, and this is at the point (0, j 4) on the RC plane. Again, it s important, for completeness, to write the 0 and not just the j 4. The points for 3 j 0 and 0 j 4, and two others, are plotted on the RC plane in Fig. 146. In practical circuits, all capacitors have some leakage resistance. If the frequency goes to zero (pure dc), a tiny current always flows, because no capacitor has a perfect insulator between its plates. In addition to this, all resistors have a little capacitive reactance because they occupy a finite physical space. So there is no such thing as a mathematically perfect resistor, either. The points 3 j0 and

