The graph given below represents $I-V$ characteristics of a Zener diode. The part of the characteristics curve that is most relevant for its operation as a voltage regulator is

In the circuit shown, what will be the current through the $6 V$ zener diode?

In the given circuit,the current through the zener diode is ...... $mA$.

Zener breakdown occurs in a $p-n$ junction having $p$ and $n$ both :

In a Zener diode,the reverse bias voltage is $3 \ V$ and the width of the depletion region is $300 \ \mathring{A}$. The electric field intensity will be $\dots \ V/cm$.

Two Zener diodes ($A$ and $B$) having breakdown voltages of $6\, V$ and $4\, V$ respectively,are connected as shown in the circuit below. The output voltage $V_{0}$ variation with input voltage linearly increasing with time,is given by: $(V_{\text{input}} = 0\, V$ at $t = 0)$ (figures are qualitative).