Resistance Coils, Mounted.

Show how resistance varies with diameter, length and type of wire. Five coils are permanently mounted on a sturdy base, their wire lengths in two to one ratios to simplify computations. 6 binding posts, instructions. Needs batteries. Wire coils include: # 22 copper wire (10m); # 28 copper (10m); # 22 copper (20m); # 28 copper (20m);# 22 German silver (10m). For ohmeter or Wheatstone Bridge.