Exp. 114, To see what is meant by "divided circuits" and "shunts."--Divided Circuits; Shunts.--Exp. 115, To see what is meant by "short circuits."
Electromotive Force.--Unit of E. M. F.; The Volt.--Exp. 116, To see whether the E. M. F. of a cell depends upon the materials used in its construction.--Discussion.--Electromotive Series.--Exp. 117, To see whether the E. M. F. of a cell depends upon its size.--Discussion.
Resistance.--Exp. 118, To study the general effect of "resistance" upon a current.--External Resistance; Internal Resistance; Unit of Resistance; The Ohm.--Resistance Coils; Resistance Boxes.--Simple Resistance Coil.--Exp. 119, To test the power of various substances to conduct galvanic electricity.--Conductors and Nonconductors.--Exp. 120, To find the effect of sulphuric acid upon the conductivity of water.--Internal Resistance.--Exp. 121, To find what effect the length of a wire has upon its electrical resistance.--Discussion.--Exp. 122, To find what effect the size (area of cross-section) of a wire has upon its electrical resistance.--Discussion.--Exp. 123, To compare the resistance of a divided circuit with the resistance of one of its branches. Discussion.--Exp. 124, To study the effect of decreasing the resistance in one branch of a divided circuit.--Current in Divided Circuits.
CHAPTER XIX. MEASUREMENT OF RESISTANCE 130
Exp. 125, To study the construction and use of a simple Wheatstone's Bridge.--The Simple Bridge.--Equipotential Points.--Example.--Exp. 126, To measure the resistance of a wire by means of Wheatstone's Bridge; the "bridge method."--Allowances for Connections.--Exps. 127-137, To measure the resistances of various wires, coils, etc., by the "bridge method."--Table.--Exp. 138, To study the effect of heat upon the resistance of metals.--Effect of Heat upon Resistance.--Exp. 139, To measure the resistance of a wire by the "method of substitution."--Simple Rheostat.--Exp. 140, To measure the E. M. F. of a cell by comparison with the two-fluid cell.--Exp. 141, To measure the internal resistance of a cell by the "method of opposition."
Strength of Current.--Unit of Current Strength; The Ampere.--Measurement of Current Strength.--The Tangent Galvanometer.--The Ammeter.--The Voltameter.--Unit of Quantity; The Coulomb.--Electrical Horse-power; The Watt.--Ohm's Law.--Internal Resistance and Current Strength.--Exp. 142, Having a cell with large plates, to find how the strength of the current is affected by changes in the position of the plates, the external resistance being small.--Exp. 143, Same as Exp. 142, but with small plates.--Exp. 144, To find whether the changes in current strength, due to changes in internal resistance, are as great when the external resistance is large, as they are when the external resistance is small.--Discussion, with examples.--Arrangement of Cells and Current Strength.--Cells in Series.--Cells Abreast.--Exp. 145, To find the best way to join two similar cells when the external resistance is small.--Exp. 146, To find the best way to join two similar cells when the external resistance is large.--Best Arrangement of Cells.