Two ideal diodes are connected to a battery as shown in the circuit. The current supplied by the battery is......$A$

$A$ $2\,V$ battery is connected across $AB$ as shown in the figure. The value of the current supplied by the battery when in one case the battery's positive terminal is connected to $A$ and in the other case when the positive terminal of the battery is connected to $B$ will respectively be:

The potential barrier in a $p-n$ junction diode is due to

The cause of the potential barrier in a $p-n$ junction diode is

For a $pn$ junction,the width of the space charge region (depletion layer) is approximately $\qquad$ $\mu m$.

The forbidden energy gap of $Ge$ is $0.75 \ eV$. The maximum wavelength of incident photon radiation that can generate an electron-hole pair in a $Ge$ semiconductor is ........... $\mathring{A}$.