A Textbook in Electricity and MagnetismJ. Wiley & Sons, Incorporated, 1941 - 356 oldal |
Gyakori szavak és kifejezések
acceleration ammeter Ampère's law amperes atom axis battery body Calculate called capacitance cathode cell centimeters charge Q circuit coil Compute condenser conductor connected constant copper coulomb deflection density dielectric dielectric constant direction distance dynes E₁ earth effect electric field electrolyte electromagnetic electron electron volts electrostatic emitted equal equation equipotential ergs example field due field H filament flow flux frequency galvanometer Gauss's law given gram gravitational grid heat impedance induced emf ionization ions kinetic energy Kirchhoff's law lines of force loop magnetic field mass maximum measured metal method motion moving negative charge Ohm's law ohms parallel path plane plate current pole potential difference potential drop R₁ radius resistance resultant rotation self-inductance shown in Fig solenoid solution sphere surface temperature thermocouple torque tube unit V₁ vacuum vector velocity voltage voltmeter volts wave wire zero
Népszerű szakaszok
310. oldal - In general, we mean by any concept nothing more than a set of operations; the concept is synonymous with the corresponding set of operations.
5. oldal - We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances. To this purpose the philosophers say that Nature does nothing in vain, and more is in vain when less will serve; for Nature is pleased with simplicity, and affects not the pomp of superfluous causes.
86. oldal - Accurate and minute measurement seems to the nonscientific imagination, a less lofty and dignified work than looking for something new. But nearly all the grandest discoveries of science have been but the rewards of accurate measurement and patient long-continued labour in the minute sifting of numerical results.
32. oldal - Every particle of matter in the universe attracts every other particle with a force proportional to the product of their masses and inversely as the square of the distance between them.
34. oldal - ... of those edifices, upright rods of iron made sharp as a needle, and gilt to prevent rusting, and from the foot of those rods a wire down the outside of the building into the ground, or down round one of the shrouds of a ship, and down her side till it reaches the water? Would not these pointed rods probably draw the electrical fire silently out of a cloud before it came nigh enough to strike, and thereby secure us from that most sudden and terrible mischief?
34. oldal - Electrical fluid agrees with lightning in "these particulars: 1. Giving light. 2. Colour of the light. "3. Crooked direction. 4. Swift motion. 5. Being con"ducted by metals. 6. Crack or noise in exploding. 7. Sub"sisting in water or ice. 8. Rending bodies it passes "through. 9. Destroying animals. 10. Melting metals.
37. oldal - Now the most startling result of Faraday's law Is perhaps this. If we accept the hypothesis that the elementary substances are composed of atoms, we cannot avoid concluding that electricity also, positive as well as negative, is divided into definite elementary portions, which behave like atoms of electricity.
240. oldal - Science is built up with facts, as a house is with stones. But a collection of facts is no more a science than a heap of stones is a house.
34. oldal - I say, if these things are so, may not the knowledge of this power of points be of use to mankind, in preserving houses, churches, ships, etc., from the stroke of lightning, by directing us to fix, on the highest parts of those edifices, upright rods of iron made sharp as a needle, and gilt to prevent rusting, and from the foot of those rods a wire down the outside of the building into the ground, or down round one of the shrouds of a ship, and down her side till it reaches the water...
5. oldal - In experimental philosophy we are to look upon propositions inferred by general induction from phenomena as accurately or very nearly true, notwithstanding any contrary hypotheses that may be imagined, till such time as other phenomena occur, by which they may either be made more accurate, or liable to exceptions.