DIRECT-CURRENT DYNAMOS AND MOTORS. 9 
91. 
92. 
93. 
94. 
95. 
96. 
97%. 
98. 
How is a current in any conductor of a multipolar dynamo 
related to the total current, (a) when opposite coils of the 
armature windings are cross-connected at the commuta- 
tor, (b) when the brushes are connected in parallel, 
(c) when the coils are connected by a two-circuit wind- 
ing? 
A six-pole machine furnishes a total current of 300 amperes; 
what is the current flowing in each wire, if the winding is 
cross connected, and if each conductor consists of 2 wires. 
connected in parallel? 
What must be the gauge of the wire referred to in the pre- 
ceding question, if a specific area of 8V0 circular mils per 
ampere is taken? Use Table 13, Instruction Book. 
Given a smooth armature of 9 inches diameter, how many 
No. 12 B. & S. wires can be wound on it, if the height of 
the winding space is not to exceed $4 inch, and if one-tenth 
of the circumference is used for division strips? 
A smooth ring armature of 30 inches external diameter, 22 
inches internal diameter, and 12 inches length, is wound 
with No. 8 B. & 8. wire toa uniform height of + inch. 
Find the number of conductors, the total length of wire 
and its total resistance, assuming that the entire interior 
surface is covered by the winding. 
A toothed armature of 21 inches diameter has 88 slots, each 
% inch wide and 1,% inches deep; how many No. 10 
B. & 8. wires can be wound on it? 
Determine the sizeof conductor required for a 50 K. W. 125- 
volt bipolar dynamo to be used under ordinary conditions, 
Find the sectional area required for the armature conductor 
of a 1200 K. W. 8-pole railway generator (550 volts) cor 
central station use. 
