1-25Similarly, the following resistance ratio exists between the four arms of the bridge, just as in theresistance bridge expression discussed earlier:orThus, both the unknown resistance and capacitance, Rxand C_{x}, can be estimated in terms of knownresistance R1, R2, R_{s}, and known capacitance C_{s}.In figure 1-7, for example, we know that R1 is 20 ohms, R2 is 40 ohms, R_{s} is 60 ohms, and C_{s }is 10microfarads. We can find the values of C_{x} and R_{x} by using the respective formulas as follows:andQ-19.When a bridge is used to measure resistance, what is the value of R_{x} if R1 equals 80 ohms, R2equals 120 ohms, and R3 equals 280 ohms?INDUCTANCE BRIDGE.—The value of the unknown inductance L_{x}may be determined by meansof the simple bridge circuit shown in figure 1-8. Ratio arms R1 and R2 are accurately calibrated resistors.L_{s} is a standard inductor with a known inductance; R_{s} is the known resistance, and R_{x} represents theresistance of the unknown inductor.