334. Directions. (A) Measure the resistance of the coil of No. 25 copper wire (No. 90). (See [Exp. 126] for details and the Note, [Exp. 129].)
335. Directions. (A) Measure the combined resistance of the two coils used in Exps. 129 and 130, when they are joined in "series"; that is, when one end of one coil is joined to one end of the other by means of a metal plate, the free ends being connected to the bridge ([Exp. 126]). The current has to travel through the entire length of both coils.
(B) Compare this result with the sum of their separate resistances found in Exps. 129 and 130. (See [Exp. 129], Note.)
336. Directions. (A) Measure the resistance of the two coils ([Exp. 131]) when they are joined "in parallel." (See [§ 293].) They may be joined in parallel by connecting them both to the bridge at the same time, one end of each being slipped onto 2 ([Fig. 103]), the other end of each being joined to 3. In this way the current has two paths, side-by-side, to get from 2 to 3. (See [Exp. 129], Note.)
(B) Compare this resistance with that of [Exp. 131].