The magnitude of the mid-band voltage gain of the circuit shown in figure is (assuming $${h_{fe}}$$ of the transistor to be $$100$$)

Given the Op-amps in the figure of ideal, the output voltage $${V_0}$$ is

In the figure shown, assume the op-amp to be ideal. Which of the alternatives gives the correct Bode plots for the transfer function $${{{V_O}\left( \omega \right)} \over {{V_i}\left( \omega \right)}}?$$

In the Wien Bridge oscillator circuit shown in figure, the bridge is balanced when