Explain, with the help of a circuit diagram, the working of a p-n junction diode as a half-wave rectifier.

A p-n junction diode conducts current in forward bias and blocks current in reverse bias. p-n junction diode is forward biased in positive cycle. In forward bias, resistance of diode, RD=0 or it acts as a short circuit and output voltage equals the input voltage. p-n junction diode is reverse biased in negative cycle. In reverse bias, resistance of diode, RD=∞ or it acts as an open circuit and output voltage is zero. Hence, the p-n junction allows only positive cycles to pass through them.