14. What is the proper function of a fuse?
15. Make sketch of a mica slip fuse.
16. Define sneak currents.
17. Make a diagram of a sneak-current arrester and describe its principles and working.
18. Describe a heat coil.
19. Sketch a complete line protection.
20. Where is the proper position of the fuse?
21. Which wires are considered exposed and which unexposed?
22. Why is it not necessary to install sneak-current arresters in central-battery subscribers' stations?