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Because R1 and R2 are expressed in the same units, the equation R1/R2 becomes a simple multiplication factor. This equation provides a numerical value for C_{x} and will be in the same units as C_{ s} (farad, microfarad, and so forth). Similarly, the following resistance ratio exists between the four arms of the bridge, just as in the resistance bridge expression discussed earlier: or
Thus, both the unknown resistance and capacitance, R_{ x} and C_{x}, can be estimated in terms of known resistance R1, R2, R_{s}, and known capacitance C_{ s}. In figure 17, for example, we know that R1 is 20 ohms, R2 is 40 ohms, R_{s} is 60 ohms, and C_{ s} is 10 microfarads. We can find the values of C_{x} and R_{x} by using the respective formulas as follows:
and
Q.19 When a bridge is used to measure resistance, what is the value of R_{x} if R1 equals 80 ohms, R2 equals 120 ohms, and R3 equals 280 ohms? INDUCTANCE BRIDGE.  The value of the unknown inductance L_{x} may be determined by means of the simple bridge circuit shown in figure 18. 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 the resistance of the unknown inductor. Figure 18.  Inductance bridge. The ac signal is applied to the bridge, and variable resistors R1 and R2 are adjusted for a minimum or zero deflection of the meter, indicating a condition of balance. When the bridge is balanced, the following formulas may be used to find L_{x}. (NOTE: The right side of this expression is NOT inverse as it was in the capacitance bridge.)
and
or
In figure 18, for example, the values of R1, R2, and R_{s} are 20, 40, and 60 ohms, respectively. The value of L_{s} is 10 millihenries. We can find the values of R_{x} and L_{x} by using their respective formulas as follows:
and
Thus, both the unknown resistance and inductance can be estimated in terms of the known values for R1, R2, R_{s}, and L_{ s}. Q.20 When an unknown capacitance is tested with a bridge, what is the value of C_{x} if R1 equals 70 ohms, R2 equals 150 ohms, and C_{s} equals 550 microfarads? 
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