The Cyclopædia of Electrical Engineering: Containing a History of the Discovery and Application of Electricity with Its Practice and Achievements from the Earliest Period to the Present Time : the Whole Being a Practical Guide to Artisans, Engineers and Students Interested in the Practice and Development of Electricity, Electric Lighting, Motors, Thermo-piles, the Telegraph, the Telephone, Magnets and Every Other Branch of Electrical Application, Volume 1Gebbie Publishing Company, Limited, 1891 - Electric engineering |
Common terms and phrases
acid alternating ammeter amount amperes apparatus armature core battery brass brushes cast-iron commutator conductor connected consequently considerable convolutions copper current flowing current strength curve Daniell cell deflection developed diameter difference of potential direction distance dynamo eddy currents effect electricity electrified electro-magnetic electro-motive force employed energy equal external circuit external resistance fact field field-magnet coils fixed galvanometer Grove cell heat horizontal inch increase induced instrument insulated joined length limbs lines of force machine magnet magnetising maximum measured metal method motor needle number of lines obtained ohms opposite pair parallel passing permeability piece placed plate pole-pieces poles portion position potential difference proportional reduced result revolutions per minute right angles ring rotation round screw self-induction shaft shown in fig shunt soft iron solenoid speed steel sulphate sulphuric acid tangent galvanometer temperature terminals tion varies vertical voltmeter volts wire wound zero zinc zinc sulphate
Popular passages
Page 40 - But the metre thus determined is retained as the standard of length, and one hundredth part of this length, called one centimetre, is taken as the basis of the units upon which the system now to be briefly described has been reared. A square centimetre is the area contained in a square each of whose sides is one centimetre, and a cubic centimetre is the volume contained in a cube each of whose edges is one centimetre in length. The next unit required is that of mass, or quantity of matter, and it...
Page 208 - ... and r is the radius of the circle. If, therefore, the diameter of the outside layer is actually twice that of the inside, the length of the wire in each of the larger turns, and consequently in the whole layer, will be exactly doubled, and its resistance doubled also ; and the intermediate...
Page 233 - EMF is proportional to the rate at which the lines of force are cut, it is only necessary, in order to decide this question, to ascertain whether the rate of cutting is, under the circumstances, also uniform. A little reflection will show that just when the rectangle begins to move from its position in fig.
Page xxxiv - Haüy discovered the same property in the Siberian and Brazilian topaz, borate of magnesia, mesotype, prehnite, sphene, and calamine. He also found that the polarity which minerals receive from heat has a relation to the secondary forms of their crystals, — the tourmaline, for example, having its resinous pole at the summit of the crystal which has three faces, and its vitreous pole at the summit which has six faces. In the other...
Page xiv - ... which is excited by the friction of the glass against the hand will, by dashing against the white paper, cloth, or finger, be put into such an agitation as to emit light and make the white paper, cloth, or finger appear lucid like a glowworm, and in rushing out of the glass will sometimes push against the finger so as to be felt.
Page 100 - If we increase the size of the coil, we not only increase the distance from the wire to the needle...
Page 38 - ... 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 93 - We have already defined the dyne as the unit of force, and the magnet pole of unit strength is such a one that if placed at a distance of one centimetre from a similar and equal pole, it will repel it with a force of one dyne. Consequently, the strength at any point in any field can be determined by measuring, in dynes, the repulsion at that point of a magnet pole of unit strength. In every case, then, the...
Page xxxix - When sulphuric acid diluted with three parts of water was poured upon iron filings, inflammable air was disengaged with a brisk effervescence, and at the end of a few minutes the condenser was so highly charged as to yield a strong spark of negative electricity. Similar results were obtained when charcoal was burnt on a chafing dish...
Page lix - ... the square of the current (in amperes) multiplied by the resistance (in ohms).