Avalanche breakdown is due to

In the given figure,a diode $D$ is connected to an external resistance $R = 100 \,\Omega$ and an $e.m.f.$ of $3.5 \,V$. If the barrier potential developed across the diode is $0.5 \,V$,the current in the circuit will be ........ $mA$.

$A$ semiconductor $X$ is made by doping a germanium crystal with indium $(Z = 49)$. $A$ second semiconductor $Y$ is made by doping germanium crystal with arsenic $(Z = 33)$. Both are joined end to end and connected to a battery as shown. Which of the following statements is correct?

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

The output voltage in the following circuit is (Consider ideal diode case)

When a $P-N$ junction is reverse biased,then ...