Practical Electricity

Front Cover
McGraw-Hill book Company, Incorporated, 1917 - Electrical engineering - 646 pages
0 Reviews

What people are saying - Write a review

We haven't found any reviews in the usual places.

Other editions - View all

Common terms and phrases

Popular passages

Page 42 - This rod has a north pole at one end and a south pole at the other. If the rod is cut in half, new poles appear, as in Fig.
Page 274 - ... flux. Then, the middle finger will point in the direction of the induced emf...
Page 47 - The force exerted between two magnetic poles varies inversely as the square of the distance between them. Hence the force in dynes exerted between two magnetic poles of strengths m and m' when d centimeters apart in air is defined by the equation F = mm
Page 266 - ... machinery to be stopped. 4. To aid the generating plant in carrying the maximum load (peak) which usually exists for only an hour or two. 5. To make the load on engines or prime movers more uniform, by charging the battery when the load is light. 6. To transform from a higher to a lower potential by charging the cells in series, and discharging them in parallel, or vice-versa. 7. To subdivide the voltage, and enable a three or a five wire system to be operated from a single generator.
Page 10 - ... attached. If an electron is represented by a sphere an inch in diameter, the diameter of an atom of matter on the same scale is a mile and a half. Or if an atom of matter is represented by the size of this theater, an electron is represented on the same scale by a printer's full stop.
Page 8 - ... to be thought of on this hypothesis as flying about inside the atom, as a few thousand specks like full stops might fly about inside this hall; forming a kind of cosmic system under their strong mutual forces, and occupying the otherwise empty region of space which we call the atom — occupying it in the same sense that a few scattered but armed soldiers can occupy a territory — occupying it by forceful activity, not by bodily bulk.
Page v - An elementary course in general electricity. This course gives the fundamental facts and theories relating to electricity and its present-day applications. For electrical engineering students this is a sophomore course. It is also intended to meet the needs of students in other departments who desire a general knowledge of the subject.
Page 13 - The difficulty of investigation of the constitution of an atom can be realized by considering the actual sizes and masses concerned. As a rough simile, Lord Kelvin stated that if a drop of water could be magnified to the size of the earth, the individual molecules would then be about the size of cricket balls. The opposite perhaps appeals to the imagination more. Think of the earth as made up of cricket balls, and then suppose it to shrink to the size of a drop of water. The mind cannot follow the...
Page 161 - The total resistance of a parallel circuit is equal to the reciprocal of the sum of the reciprocals of the individual resistances of the circuit.
Page 309 - Lenz's law, that the induced emf is always in such a direction as to oppose the change of current.

Bibliographic information