The logic performed by the circuit shown in figure is equivalent to :

If each diode has a forward bias resistance of $$25 ~\Omega$$ in the below circuit,

Which of the following options is correct :

A zener diode of power rating 1.6 W is to be used as voltage regulator. If the zener diode has a breakdown of 8V and it has to regulate voltage fluctuating between 3 V and 10 V. The value of resistance R_s for safe operation of diode will be

For a given transistor amplifier circuit in $$\mathrm{CE}$$ configuration $$\mathrm{V}_{\mathrm{CC}}=1 \mathrm{~V}, \mathrm{R}_{\mathrm{C}}=1 ~\mathrm{k} \Omega, \mathrm{R}_{\mathrm{b}}=100 ~\mathrm{k} \Omega$$ and $$\beta=100$$. Value of base current $$\mathrm{I}_{\mathrm{b}}$$ is