Question

3. (10pt) A strain gauge that has a nominal resistance of 350 Q and a gauge factor of 1.8 ismounted in a Wheatstone bridge, which is balanced at a zero

applied strain condition. Assume allresistors are equal when the strain gauge circuit is initially balanced with no load. The gauge ismounted on a 1 cm? aluminum rod, with Em=70 GPa. The gauge senses axial strain. The bridgeoutput is 1 mV for a bridge input of 5V. What is the applied load, assuming the rod is in uniaxialtension?

Fig: 1