Avalanche breakdown in a $PN$ junction diode is due to

$A$ waveform is applied to the following circuit. Assuming an ideal diode configuration and $R_1 = R_2$, which of the following output waveforms will be produced?

In the given circuit,the input voltage $V_{\text{in}}$ is shown in the figure. The cut-in voltage of the $p-n$ junction diode ($D_{1}$ or $D_{2}$) is $0.6\,V$. Which of the following output voltage $(V_{0})$ waveforms across the diode is correct?

$A$ $2\,V$ battery forward biases a diode. There is a drop of $0.5\,V$ across the diode which is independent of current. Also,a current greater than $10\,mA$ produces large joule heat and damages the diode. If the diode is to be operated at $5\,mA$,the series resistance to be used is:

The potential barrier in the depletion layer is due to

When and why is a $p-n$ junction called forward biased? Describe the changes that occur under such bias.