3.) A diaphragm pressure gauge employs four strain gauges to monitor the displacement of the diaphragm. The four active gauges form the arms of a Wheatstone bridge, in the way

shown in Fig. 3.23 b (see class notes too). The gauges have a gauge factor of 2.1 and resistance 120 Q. A differential pressure applied to the diaphragm results in two of the gauges on one side of the diaphragm being subject to a tensile strain of 1.0 x 10^-5 and the two on the other side a compressive strain of 1.0 x 10^-5 . The supply voltage for the bridge is 10 V. What will be the voltage output from the bridge? (20 pts) (Answer is 0.21 mV, but you need to show the work to get to this.)

Fig: 1