The output of a Wheatstone bridge is nonlinear with respect to the variations in a bridge resistance. This nonlinearity is negligible for small changes in resistance. For large variations in resistance, however, some method of calibration or linearization should be employed. One way to linearize the bridge output is to feed back (positively) the output voltage signal into the bridge supply using a feedback op-amp. Consider the Wheatstone bridge circuit shown in Figure 4.31a. Initially, the bridge is balanced with R₁ = R₂ = R₃ = R₄ = R. Then, the resistor R₁ is varied to R + δ R. Suppose that the bridge output δυo is fed back (positive) with a gain of 2 into the bridge supply υref. Show that this will linearize the bridge equation.