| BC | 3 | ||||
| tan φ | = | = | or .75 | ||
| AB | 4 |
From the table on page 451, the angle is approximately 37°.
Fig. 1,324.—Diagram for impedance of circuit containing 20 ohms resistance, and inductance of 15 milli-henrys, when the frequency is 100.
Fig. 1,325.—Diagram showing angle of lag for current containing 4 ohms resistance and 3 ohms reactance.
Circuits containing Resistance and Capacity.—The effect of capacity in an alternating current circuit is to cause the current to lead the pressure, since the reaction of a condenser, instead of tending to prolong the current, tends to drive it back.
Careful distinction should be made between capacity in series with a circuit and capacity in parallel with a branch of a circuit. The discussion here refers to capacity in series, which means that the circuit is not continuous but the ends are joined to a condenser, as shown at the right in fig. 1,326, so that no current can flow except into and out of the condenser.
