A load $($with internal resistance, R$($L$)=2*(212+1000)$Omega$)$requires V$($L$)=(2+4)$V to operate properly when the

supply voltage, E$=[24]$V$.$

a$)$Find the components used in empty box using one or combination of different practical diodes $($Si or Ge or GaAs or Zener$),$as shown in Figure $1.$

b$)$Compare this network by consider other diodes $($except from part a$)$inside the empty box with a proper diagram and

calculation so that it can drive this load at its required voltage