Fig. 1,292.—Diagram of circuit for example II.
Here the inductance is given as a fraction of a henry; this must be reduced to ohms by substituting in equation (3), page [1,038], which gives the ohmic value of the inductance; accordingly, substituting the above given value in this equation
inductance in ohms or Xi = 2π × 125 × .0034 = 2.67
Substituting this result and the given resistance in equation (1), page [1,053],
| 2.67 | ||||
| tan φ | = | = | 1.16 | |
| 2.3 |
the nearest angle from table (page 451) is 49°.
Ques. How great may the angle of lag be?
Ans. Anything up to 90°.
The angle of lag, indicated by the Greek letter φ(phi), is the angle whose tangent is equal to the quotient of the inductance expressed in ohms or "spurious resistance" divided by the ohmic resistance, that is