A general filter circuit is shown in figure

If $${R_1} = {R_2} = {R_A}$$ and $${R_3} = {R_4} = {R_B},$$ the circuit acts as a

The block diagram of two types of half wave rectifiers are shown in figure. The transfer characteristics of the rectifiers are also shown within the block

It is desired to make full wave rectifier using two half wave rectifiers. The resultant circuit will be

Two perfectly matched silicon transistors are connected as shown in the figure. Assuming the $$\beta $$ of the transistors to be very high and forward voltage drop to be $$0.7V,$$ the value of current $${\rm I}$$ is (assume diode $$(D)$$ is ideal)

In the voltage doubler circuit shown in figure, the switch $$' S '$$ is closed at $$t=0$$. Assuming diodes $${D_1}$$ & $${D_2}$$ to be ideal, load resistance to be infinite and initial capacitor voltages to be zero, the steady state voltage across capacitors $${C_1}$$ & $${C_2}$$ will be