2-10. 2-11. 2-12. 2-13. 2-14. Conductors used for connecting distribution transformers to the feeder circuit are called 1. distribution mains 2. secondary  mains 3. primary  mains 4. service  drops The primary purpose of a distribution transformer is to 1. increase  voltage  to  primary distribution   levels 2. protect the primary feeders against  overloads 3. protect  secondary  feeders against overloads 4. decrease voltage to utilization levels What overhead circuits carry power from  the  transformer  to  the customer  through  one  or  more service drops? 1. 2. 3. 4. Single-phase  primaries  only Single- or three-phase primaries Single-phase   secondaries   only Single-  or  three-phase secondaries To neutralize an underground branch circuit  in  the  distribution  system, which of the following control or protective devices should the electrician open? 1. An air switch 2. An oil switch 3. A  recloser 4. A distribution cutout Lightning arresters are required at which of the following locations? 1. At  all  substations 2. On the primary side of all transformers 3. At all distribution centers and capacitor  banks 4. All of the above Figure 2B IN  ANSWERING  QUESTIONS  2-15  THROUGH  2-20, REFER TO FIGURE 26. 2-15. What type of distribution line is identified by the letter “A”? 1. Primary  feeder 2. Primary  main 3. Secondary  main 4. Service  drop 2-16. What type of distribution line is identified by the letter “B”? 1. Primary  feeder 2. Primary  main 3. Secondary  main 4. Service  drop 2-17. What type of distribution line is identified  by  the  letter  “C”? 1. Primary  feeder 2. Primary  main 3. Secondary  main 4. Service  drop 9