THE DESIGN OF DIRECT-CURRENT 
301. 
302. 
303. 
304. 
305. 
306. 
307. 
308. 
309. 
310. 
311. 
312. 
313. 
314. 
DYNAMOS AND MOTORS 
Name the four methods of winding magnets for direct- 
current dynamos and motors. 
How are constant-current arc-light generators excited? 
How are the magnet coils of railway motors arranged? 
How may direct-connected or geared motors be wound if 
they are intended for fairly constant load? 
What winding is used for variable-speed motors? 
What method of excitation is employed for constant-spee 
motors with variable load? 
How are constant-voltage generators wound? 
How must motors be wound if a strong starting torque is 
required? 
What winding is used for constant-potential generators 
«driven by power of widely varying speed? 
What winding should be employed for motors required te 
run with constant spood at varying load? 
One of two similar magnet cores is wound with 250 turns 
of wire and excited by a current of 15 amperes; the 
other is wound with 5,000 turns and excited by a cur- 
rent of ¢ of an ampere; which is the stronger magnet? 
How does differential winding differ from ordinary com- 
pound winding? 
Give formula for the number of turns of a series winding. 
State rule for proportioning the size of wire for a series 
winding. 
