Distinguish between half wave and full wave rectifier ?

Half wave rectifier :
i) One p-n jnction diode is used
ii) Only positive half cycle of input A.C signal is converted into rectified D.C output
iii) Efficiency $\mathrm{\eta }=\frac{0.406{\mathrm{R}}_{\mathrm{L}}}{{\mathrm{r}}_{\mathrm{f}}+{\mathrm{R}}_{\mathrm{L}}}$
iv) Maximum efficiency is 40.6%
v) The number of D.C pulses per second is equal to frequency of applied A.C
Full wave Rectifier :
i) Two p-n junction diodes are used
ii) Both positive and negative half cycles of input A.C signals are converted into rectified D.C output
iii) Efficiency $\mathrm{\eta }=\frac{0.812{\mathrm{R}}_{\mathrm{L}}}{{\mathrm{r}}_{\mathrm{f}}+{\mathrm{R}}_{\mathrm{L}}}$
iv) Maximum efficiency is 81.2%
v) The number of D.C pulses per second is equal to twice the freuqency of applied A.C