When a $p-n$ junction diode is in forward bias,which type of charge carriers flows in the connecting wire?

What is breakdown voltage and saturation current?

When a diode is forward biased,it has a voltage drop of $0.5\, V$. The safe limit of current through the diode is $10\, mA$. If a battery of emf $1.5\, V$ is used in the circuit,the value of minimum resistance to be connected in series with the diode so that the current does not exceed the safe limit is $.....\, \Omega$.

When a reverse bias is applied to a $p-n$ junction diode,what happens to the potential barrier?

The curve between charge density $\rho$ and distance $r$ near a $p$ - $n$ junction is best represented by

The value of net resistance of the network as shown in the given figure is: