Applied Electricity Paper 2 , Nov/Dec. 2010  
Questions:   1 2 3 4 5 6   Main
General Comments

Question 2

(a) State two losses that occur in a d.c.machine.

From fig.8, calculate the:
(i)load current, IL
(ii)armature current, Ia
(iii)armature current, Ia
(iii)generated e.m.f.


The expected answers were:
1. (a)(Any two ofthe following
(i) Copper loss
(H) Frictional windage loss
(iii) Brush contact loss
(iv) Iron loss
(b)Terminal voltage, V = 230V
Power to the load, PL = 1150
Armature resistance, Ra = 0.20

The question was on Direct Current Machine. Many of the candidates who attempted this question gave the losses correctly but was very difficult to do any calculation due to incomplete information

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