What is the current flowing through the given circuit? $A$ given diode is an ideal diode.

$D_1$ and $D_2$ are two ideal diodes. Find the values of $i_1$ and $i_2$.

An electron in the $n$-region of a $p-n$ junction moves towards the junction with a speed of $5 \times 10^5 \ m/s$. If the barrier potential of the junction is $0.45 \ V$,then the speed with which the electron enters the $p$-region after penetration through the barrier is (Charge of the electron $e = 1.6 \times 10^{-19} \ C$ and mass of the electron $m = 9 \times 10^{-31} \ kg$).

The circuit contains two diodes,each with a forward resistance of $50\, \Omega$ and an infinite reverse resistance. If the battery voltage is $6\, V$,the current through the $120\, \Omega$ resistance is $mA$.

Which of the following circuits is reverse-biased?

Two statements are given below:
$A$. When the forward bias voltage across a $p-n$ junction diode increases above a certain threshold voltage,the diode current increases significantly.
$B$. This current is called reverse saturation current.
Choose the correct answer from the options given below: