When forward bias is applied to a $p-n$ junction,then what happens to the potential barrier $(V_B)$ and the width $(X)$ of the depletion region?

On which of the following does the barrier potential of a $P-N$ junction diode $NOT$ depend?

In the following circuits,which one of the diodes is reverse biased?

If no external voltage is applied across a $P-N$ junction,there would be:

The cut-in voltage for a silicon diode is approximately $V$.

Statement $I :$ When a $Si$ sample is doped with Boron,it becomes $P$-type and when doped by Arsenic it becomes $N$-type semiconductor such that $P$-type has excess holes and $N$-type has excess electrons.
Statement $II$ : When such $P$-type and $N$-type semiconductors are fused to make a junction,a current will automatically flow which can be detected with an externally connected ammeter.
In the light of above statements,choose the most appropriate answer from the options given below.