What is a junction diode? What is meant by forward-bias and reverse-bias in the case of p-n junction diode? Distinguish between the two biases.

With reference to a semiconductor diode, what is meant by forward bias?

With reference to a semiconductor diode, what is meant by depletion region?

Explain the formation of depletion region and potential barrier in a $p$-$n$ junction diode. State how the thickness of depletion region changes when the $p$-$n$ junction diode is forward biased.

Explain the formation of depletion region and potential barrier in a $p$-$n$ junction diode. State how the thickness of depletion region changes when the $p$-$n$ junction diode is reverse biased.

Draw a circuit diagram for $p$-$n$ junction diode in forward bias. Sketch and discuss the voltage versus current graph for the same.

Draw a circuit diagram for $p$-$n$ junction diode in reverse bias. Discuss voltage-current characteristic curve in the reverse bias, explaining avalanche breakdown.

Draw a labelled circuit diagram of a half-wave rectifier and give its output wave-form.