Applied Electricity Paper 2 , Nov/Dec. 2012
 Questions: 1 2 3 4 5 6 Main
Weakness/Remedies
Strength

Question 5

 (a) Draw the circuit diagram of the following d.c. generators:       (i)        series;       (ii)       shunt. (b) A d.c. shunt generator supplies a current of 28 A at 400 V. The armature and field resistances are 0.5 Q and 200 Q respectively. Calculate the:       (i)        field current;       (H)      armature current. The expected answers were: (a) ~~.                                                                       f""'-.....;,0;,;;;,0"">.1).          _ ..              '                    I                                       v: .. ()             .' . '7-. ~d'''                                                                 r-, ~                                             ,.,' r.\ .••• . "t) . 1                                                                        ~l____________ ' __ ~l                  . ~cU:.~~ (a) ii~~ . VT .~ (b) (i)   =~=2A 200                                 (ii)       Ia = IL + If = 28 + 2 = 30 A

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Observation

The question was on Alternating Current Machines. It was well
attempted by the candldates. However, part (a) was not well done by
many candidates and this was attributed to their level of understanding and
exposure.