This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1894 Excerpt: ... grooved and carries a coil of many turns, whose ends are connected to the bindingscrews, a, and which is used for measuring small currents. These coils are mounted so as to turn freely round the vertical pillar at the bottom, and this pillar is carried by the massive circular base, which is provided with levelling ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1894 Excerpt: ... grooved and carries a coil of many turns, whose ends are connected to the bindingscrews, a, and which is used for measuring small currents. These coils are mounted so as to turn freely round the vertical pillar at the bottom, and this pillar is carried by the massive circular base, which is provided with levelling screws, so that the plane of the coils can be adjusted until it is truly vertical. At the common centre of the circles there is rigidly supported the box, M, containing the suspended mirror, with the little magnets at its back, as in the ordinary reflecting galvanometers. The mirror and magnets are suspended by a long fibre, which hangs down from the screw, s, at the top of the tube. The movements of the mirror and its magnets are observed in Fin. i97.--Htandurd Tangent Galvanometer. Standard Tangent Galvanometer. 375 the usual way, with either telescope or lamp and scale. The controlling field usually employed is that of the earth and the strength of this field has to be determined carefully by independent experiments. In using the instrument it must first be set so that the plane of the ring, rr, lies in the magnetic meridian. It should then be carefully levelled until the little magnet and mirror lie at the centre of the large circle. If these adjustments are carefully made, we know that the lines of force at the needle, due to a current in the coil, will be at right angles to the lines of force of the earth's field. When this is the case, the conditions for the tangent law referred to below, and from which the instrument takes its name, are fulfilled. When the instrument is properly constructed and adjusted the calculation of the current that will produce a particular deflection is very simple. Thus, if C be the current in the ring, in ampere...
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Add this copy of The Electric Current: How Produced and How Used to cart. $76.98, new condition, Sold by Booksplease rated 4.0 out of 5 stars, ships from Southport, MERSEYSIDE, UNITED KINGDOM, published 2015 by Arkose Press.