Electricity, generators, motorsAmerican School of Correspondence, 1903 - Engineering |
Common terms and phrases
alternating current ampere-turns amperes armature conductors armature core armature current armature windings battery brushes carbon characteristic curve charge compound dynamo conductor connected in parallel connected in series constant copper counter E. M. F. cross section current passes decrease deflection density diameter direct current dynamo electrical efficiency electrical energy electrical losses electromotive force equal external circuit field coils field magnets field strength field winding formula galvanometer greater heat Hence horse-power hysteresis increase induced insulation internal resistance joules length lines of force lines per square load magnetic circuit magnetic field magnetic flux magnetic lines magnetizing force measured metal method number of turns obtained Ohm's law ohms output plate pole pieces position R₂ revolutions per minute rheostat ring rotation series coils shown in Fig shunt dynamo shunt motor Solution speed square inch temperature terminals torque total current total E. M. F. unit varies voltage voltmeter volts watts wire Zinc
Popular passages
Page 17 - Ike current is directly proportional to the electromotive force and inversely proportional to the resistance.
Page 8 - If a circuit is made up of several different materials joined in series with each other, the resistance of the circuit is equal to the sum of the resistances of its several parts. In calculating the resistance of such a circuit, the resistance of each part should first be calculated, and the sum of these resistances will be the total resistance of the circuit.
Page 18 - Ohm's law may therefore be expressed by the following equation: where / is the current in amperes, E the electromotive force in volts and R the resistance in ohms. It is therefore evident, that if the electromotive force and resistance are known the current may be found, or if any two of the three quantities are known the third may be found.
Page 25 - In general, for any number of conductors connected in parallel, the joint resistance is found by taking the reciprocal of the sum of the reciprocals of the separate resistances.
Page 38 - Is the amount of heat required to raise the temperature of 1 pound of water 1° Fahrenheit.
Page 6 - The unit difference of magnetic potential exists between two points, when it requires the expenditure of one erg of work to bring a unit magnetic pole from one point to the other against the magnetic forces. Field Intensity.
Page 35 - ... produce chemical changes. The unit of mechanical energy is the amount of work performed in raising a mass of one pound through a distance of one foot, and is called the foot-pound. The work done in raising any mass through any height, is found by multiplying the number of pounds in that mass by the number of feet through which it is lifted. Electrical work may be determined in a corresponding manner by the amount of electricity transferred through a difference of potential. The Joule. The joule...
Page 6 - As the area of a circle is proportional to the square of its diameter, it follows that the resistances of round conductors are inversely proportional to the squares of their diameters.
Page 6 - When another ring is added, the first will in turn induce a north pole at the top and a south pole at the bottom of the second ring.
Page 3 - C causes it to move along the rails to the right or left according to the direction of the current.