In the figure shown, $R_T$ represents a resistance temperature device $(RTD)$, whose characteristic is given by $R_T=R_\circ(1+\alpha T),$ where $R_\circ=100\: \Omega, \: \alpha=0.0039^\circ C^{-1}$ and $T$ denotes the temperature in $^\circ C$. Assuming the opamp to be ideal, the value of $V_\circ$ in volts when $T=100^\circ C$, is _____________ $V$.
