(a) Figure Q4(a) shows an amplifier circuit. Identify the configuration of the amplifiercircuit. Also prove that: V_{o u t}=-\frac{R_{2}}{R_{1}} \times V_{i n} You must show all the mathematical steps to

derive the above equation. (b) The available values of the colour-coded carbon resistors in the store are 1k2,5k2, 10kn and 100k2. The peak signal requirement of an electronic circuit is100mV whereas only - 5mV signal could be generated from a Hall Effect sensor.Using the circuit shown in Figure Q4(a), suggest the correct values of R1 and R2 to achieve the required input to the above circuit. Clearly define the procedure you will carry out to obtain the correct values of the resistors.[4 Marks] (c) Figure Q4(b) connects two semiconductor diodes in forward and reverse biased configurations. Diode D1 has a forward saturation voltage of 0.7 Volt and D2 has the saturation voltage of 0.2 Volt. The leakage current in reverse biased configuration specified by the manufacturer is 0.5mA. Find the voltages at points Vi and V2 as shown in the diagram. Clearly show all the steps you have carried out in obtaining the voltages at the above points.[4 Marks] (d) A good use of the operational amplifier is to sum amplitude of more than one signal. Using an operational amplifier, construct a circuit diagram which can be used to add three voltages V1, V2 and V3 (each voltage signal has same frequency but different amplitude) and then prove that the output voltages Vo is equal to the sum of the input voltages with an inverted sign. If you make any assumption, it should be clearly stated.[10 Marks]