The current through the ammeter (neglecting internal resistance) in the following circuit is

Avalanche breakdown in a $PN$ junction diode is due to

When a semiconducting device is connected in series with a battery and a resistance, a current is found to flow in the circuit. If, however, the polarity of the battery is reversed, practically no current flows in the circuit. The device may be

$Ge$ and $Si$ diodes start conducting at $0.3\,V$ and $0.7\,V$ respectively. In the following figure,if the $Ge$ diode connection is reversed,the value of $V_0$ changes by: ...... $V$ (assume that the $Ge$ diode has a large breakdown voltage).

In a $P-N$ junction,which of the following statements is correct regarding the potential?

When a $p-n$ junction diode is forward biased,