In the given circuits $(a)$,$(b)$,and $(c)$,the potential drop across the two p-n junctions are equal in:

The ratio of forward bias resistance to reverse bias resistance of a $P-N$ junction is approximately .......

Two identical $P-N$ junctions are connected in series with a battery in three ways as shown in the figure. In which two circuits will the potential difference across the $P-N$ junctions be equal?

Suppose the thickness of the depletion layer in a $P-N$ junction is $10^{-6} \ m$ and the value of the depletion barrier is $0.1 \ V$. Then the electric field is ....... $V \ m^{-1}$.

The cut-off voltage of the diodes (shown in figure) in forward bias is $0.6 \,V$. The current through the resistor of $40 \,\Omega$ is ........... $mA$.

Which of the following is correct with respect to the following statements? Due to diffusion of electrons from $n$ to $p$-side:
$I$. electrons are accumulated in the depletion region.
$II$. electron drift current is from $p$-side to $n$-side.
$III$. an ionised donor is left in the $n$-region.
$IV$. electrons of $n$-side come to $p$-side and electron-hole combination takes place in $p$-side.
Select the correct option from the following.