Question

# (a) A broadcasting station transmits a 100µV signal at 1010 kHz. It is aimed to apply this signal to a parallel LC tuning circuit. Design the components of the tuning circuit to give a Q-factor of 200. It is required to feed this signal to an amplifier with the input impedance of 500kN. Sketch the circuit diagram of your suggested components. Also, draw a vector diagram to show the current components of the tuning circuit.[9 Marks] (b) Sketch the time domain response curve of the circuit designed in part (a). Label your sketch with the calculated values of impedance, tuning frequency and 3dBpoints to mark the signal bandwidth.[6 Marks] (c) A capacitor bank is made of seven small capacitors connected in series and parallel configurations between two points A and B. If the capacitor bank is represented with the following mathematical expression: C_{T}=\left[C_{5} \|\left\{C_{3}+\left(C_{1} \| C_{2}\right)\right\}\right]+C_{7}+\left(C_{4} \| C_{6}\right) Draw the circuit diagram labelling all seven capacitors on your diagram. Also calculate value of C2 if the total capacitance CT is given as 1.06 x 10-4 F and C1,C3, C4, Cs, C6 and C7 are 10pF, 1µF, 90mF, 50mF, 5µF and 100µF respectively.  Fig: 1  Fig: 2  Fig: 3  Fig: 4  Fig: 5