PROBLEMS 



1. A four-pole dynamo has to be designed with an induc- 

 tion factor equal to 8. The armature is connected in series, 

 with 480 surface conductors. Find the useful lines per pole. 



0-88 x 10 6 . 



2. A bipolar dynamo has 4'2 x 10 useful lines per pole, 

 and 220 surface conductors. Find the torque for a current 

 of 75 amperes. 980. 



3. A bipolar dynamo has 800 surface conductors. The 

 torque for 54 amperes, as measured by the method described 

 on p. 8, is 846 inch-pounds, including that due to friction 

 and hysteresis, which amounts to 78 inch-pounds. Find the 

 useful lines per pole. 8'36 x 10 6 . 



4. A direct connected generator is running at 400 r p.m. 

 when the terminal tension on open circuit is 250 volts. 

 Find the torque on the shaft for 500 amperes in the 

 armature. 26,400. 



5. A four-pole railway generator has its armature con- 

 nected in parallel with 440 surface conductors. The internal 

 resistance is 0-04 ohm. When running at 450 r.p.m. the 

 output is 600 amperes at 558 terminal volts. Find the 

 number of useful lines per pole. 17'5 x 10 6 . 



6. A ten-pole railway generator has its armature con- 

 nected in parallel with 1,440 surface conductors, and is to 

 deliver 1,500 amperes at 550 terminal volts when running at 

 80 r.p.m. Find the number of useful lines per pole, (1) con- 

 sidering the internal resistance, which is 0'012 ohm, (2) 

 neglecting the resistance. 29'6 x 10 G and 28'7 x 10 6 . 



