(a) Four diodes are connected in a circuit as shown. In the positive cycle, A is more positive than B. i) In the negative half-cycle, which diodes are reversed bias?

ii) Explain briefly what would happen if D2 were shorted in this circuit. iii) What would happen if D2 were open? (b) Design a power supply to deliver a regulated DC supply of 12 V, with a peak-to-peak ripple under 50mV. You may use US or UK line voltage as the input source. Assume the Zener resistance is equal toX ohms. i) Draw the circuit diagram and label each component. ii) Calculate the peak secondary voltage, the DC voltage measured across the capacitor and the ripple in this voltage (before regulation). 111) Describe two limits on load voltage and current that relate to the safe operation of the diodes in your design.