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

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

A general filter circuit is shown in figure

The output of the filter in above is given to the circuit shown in figure The gain $${V_S}$$ frequency characteristic of the $$0/p$$ $$\left( {{V_0}} \right)$$ will be

The input signal $${V_{in}}$$ shown in the figure is a $$1$$ $$kHz$$ square wave voltage that alternates between $$+7V$$ and $$-7V$$ with a $$50\% $$ duty cycle. Both transistors have the same current gain, which is large. The circuit delivers power to the load resistor $${R_L}.$$ What is the efficiency of this circuit for the given input? Choose the closest answer.