1.) A metallic strain gauge has a resistance of 350 ohms at zero strain. The strain gauge is originally 1-m-long. Determine the resistance (in ohms) of the gauge when is strained axially by 1cm.
2.) A metallic wire embedded in a strain gauge is 4.2 cm long with a diameter of 0.07mm. The gauge is mounted on the upper surface of a cantilever beam to sense strain. Before strain is applied, the initial resistance of the wire is 64Ω. Strain is applied to the beam, stretching the wire 0.1 mm, and changing its electrical resistivity by 2 x10-8ohm*m.If Poisson's ratio for the wire is 0.342, find the change in resistance in the wire due to the strain. Please round the resistance value to the nearest hundredth ohm.
3.) A strain gauge with a gauge factor equal to 2.05 and an unstrained resistance equal to R=125 ohm is used with a Wheatstone bridge transducer with R=125 ohm, and a voltage divider transducer having ei= 5 V and Ro= 100 ohm. For a 1% increase in strain (E=(Li-Lo)/L), determine
(a) The % change in resistance.
(b) The output voltage, eo, for the unstrained condition with both transducers.
(c) The output voltage for the strained condition with both transducers. Comment on the change in voltage that occurs when going from the unstrained to the strained condition for both transducers, which is more significant?