Answer to Question #38841 in Electric Circuits for Tarik F Eltaeib

Question

Consider aWheatstone bridge circuit using a resistive temperature sensor Rx as shown
in Figure 1.2. Further assume that R1 = 10 and R3 = 20. Assume that the current
temperature is 80 ◦F and Rx (80) = 10. You wish to calibrate the sensor such that the
output voltage VOUT is zero whenever the temperature is 80 ◦F.
(a) What is the desired value of R2?
(b) What is the output voltage (as a function of the supply voltage) at a temperature of
90 ◦F, when this increase in temperature leads to an increase in resistance of 20%
for Rx?