Q9. With reference to the paralleling of a.c. generators:
(a) outline the requirements of synchronisation; (2)
(b) explain how KW power is shared; (1)
(c) explain how K var power is shared; (1)
(d) state SIX types of damage that may be caused when machines are incorrectly synchronised.(6)
Q10.During a complete loss of electrical power, essential vital services can be maintained by means of an Uninterruptable Power Supply (UPS).
(a)Describe, with the aid of a block diagram, the operation of an a.c. input UPS arrangement. (7)
(b)List SIX essential services that the UPS may support. (3)
Q11. (a) With reference to an alkaline battery cell:
(i) describe a typical cell, stating the materials used; (4)
(ii) describe the electro-chemical process that takes place during discharge and charge. (2)
(iii) state the effect of overcharge. (2)
(b) State the advantages of an alkaline cell compared with a lead acid cell. (2)
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