A strain gauge of 120O with a gauge factor 2 is used to measure the longitudinal strain developed in a cylindrical bar which has a diameter of 100mm and Young's Modulus of 5 x 1010Pa. A compressive force of 2 x 106N is applied to the bar. The strain gauge is connected to a Wheatstone Bridge with a supply voltage of 5V d.c. and other three resistor values are 120O each.
a. Determine the resistance value of the strained gauge.
b. Draw the Wheatstone Bridge circuit arrangement, showing the position of the strain gauge.
c. Determine the balance condition of the Wheatstone Bridge.
d. Determine the output voltage of the Wheatstone Bridge with the strained gauge.
e. If a dummy strain gauge is used to compensate the resistance change Rt caused by the temperature, indicate all the possible dummy strain positions on the graph drawn in (b).