A Text-book of Physics

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Alexander Wilmer Duff
P. Blakiston's Son & Company, 1909 - Physics - 698 pages
 

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Page 550 - The unit of resistance shall be what is known as the international ohm, which is substantially equal to one thousand million units of resistance of the centimeter-gram-second system of electro-magnetic units, and is represented by the resistance offered to an unvarying electric current by a column of mercury at the temperature of melting ice fourteen and four thousand five hundred and twenty-one ten-thousandths grams in mass, of a constant cross-sectional area, and of the length of one hundred and...
Page 579 - The unit of current shall be what is known as the international ampere, which is one-tenth of the unit of current of the centimeter-gram-second system of electro-magnetic units, and is the practical equivalent of the unvarying current, which, when passed through a solution of nitrate of silver in water in accordance with standard specifications, deposits silver at the rate of one thousand one hundred and eighteen millionths (.001118) of a gram per second.
Page 72 - The measure of the work done by a force is the product of the force and the distance through which it moves its point of application in the direction of the force.
Page 272 - It is impossible by means of inanimate material agency to derive mechanical effect from any portion of matter by cooling it below the temperature of the coldest of the surrounding objects.
Page 586 - ... As a unit of electromotive force, the international volt, which is the electromotive force that, steadily applied to a conductor whose resistance is one international ohm, will produce a current of one international ampere, and which is represented sufficiently well for practical use by \\\% of the electromotive force between the poles or electrodes of the voltaic cell known as Clark's cell, at a temperature of 15° C., and prepared in the manner described in the accompanying specification...
Page 257 - The rate of cooling of a body is proportional to the difference between the temperature of its surface and that of its surroundings.
Page 585 - The unit of electro-motive force shall be what is known as the international volt, which is the electro-motive force that, steadily applied to a conductor whose resistance is one international ohm, will produce a current of an international ampere...
Page 355 - These figures relate to the time that light takes to travel a distance equal to the diameter of the earth's orbit about the sun.
Page 398 - AA' and BB' at the points A' and B', which determine the position and magnitude of the image. Since the point A' lies above the principal axis when the image is on the same side of the lens as the object, and...
Page 579 - As a unit of current, the international ampere, which is onetenth of the unit of current of the CGS system of electromagnetic units, and which is represented sufficiently well for practical use by the unvarying current which, when passed through a solution of nitrate of silver in water, and in accordance with accompanying specifications, deposits silver at the rate of 0.001118 gramme per second.

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