In the circuit shown, assume that the opamp is ideal. If the gain ($${V_0}/{V_{in}}$$) is -12, the value of R (in K$$\Omega $$) is _____.

Assuming that the Op-amp in the circuit shown is ideal, V₀ is given by

In the circuit shown, the op-amp has finite input impedance, infinite voltage gain and zero input offset voltage. The output voltage V_out is

In the voltage regulator circuit shown in the figure, the op - amp is ideal. The BJT has V_BE = 0.7 V and $$\beta $$ = 100, and the Zener voltage is 4.7 V. For a regulated output of 9 V, the value of R (in $$\Omega $$) is ______