Differentiate between half-wave and full-wave rectification. With the help of a circuit diagram, explain the working of a full-wave rectifier.

In half wave rectification there is output in one half of the input cycle, whereas in full wave rectification output is obtained for both half cycles of the input (positive and negative). Working of full wave rectifier: Suppose the input voltage to A with respect to the centre-tap at any instant is positive. At that instant, voltage at B being out of phase will be negative. So diode $\displaystyle D_{1}$ gets forward biased and conducts (while $\displaystyle D_{2}$, being reverse biased, is not conducting). Hence during this positive half cycle we get an output current (and output voltage across the load resistor $\displaystyle R_{L}$). In the course of the ac cycle when the voltage at A becomes negative with respect to the centre tap, the voltage at B would be positive. In this part of the cycle diode $\displaystyle D_{1}$ would not conduct but diode $\displaystyle D_{2}$ would, giving an output current and output voltage (across $\displaystyle R_{L}$) during the negative half cycle of the input ac.