An electron beam is accelerated by a potential difference $V$ to hit a metallic target to produce $X-$rays. It produces continuous as well as characteristic $X-$rays. If ${\lambda }_{min}$ is the smallest possible wavelength of $X-$ray in the spectrum, the variation of $\log \left({\lambda }_{min}\right)$ with $\log \left(V\right)$ is correctly represented in :

A zener diode of power rating $2 \mathrm{W}$ is to be used as a voltage regulator. If the zener diode has a breakdown of $10 \mathrm{V}$ and it has to regulate voltage fluctuated between $6 \mathrm{V}$ and $14 \mathrm{V}$, the value of $R_s$ for safe operation should be _____ $\Omega$ .

A circuit is arranged as shown in figure. The output voltage $V_o$ is equal to __________ $\mathrm{V}.$

For the given circuit, the power across zener diode is _____ $\mathrm{mW}$.