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. 1888 Excerpt: ...horizontal field of the earth and G represents the field due to the coil; then the resultant or joint effect of these two magnetic forces is a magnetic force represented by the diagonal, E, of the parallelogram formed on H and G as sides. At the centre of the circular conductor, suppose a very small magnetic needle to ...
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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. 1888 Excerpt: ...horizontal field of the earth and G represents the field due to the coil; then the resultant or joint effect of these two magnetic forces is a magnetic force represented by the diagonal, E, of the parallelogram formed on H and G as sides. At the centre of the circular conductor, suppose a very small magnetic needle to be suspended. It will take up a certain direction which depends upon the direction of the resultant force, E. The needle, in fact, lies along the direction of the resultant magnetic force. By means of a scale of degrees it is easy to find the angle which the direction of the needle makes with the meridian, that is to say, the angle O C P, included between the direction of H and the direction of E. We have now these two facts: we suppose ourselves to know the value of H, or the earth's magnetic field, and the value of the angle which the resultant force E, due to the joint effect of the magnetic force of the earth and the coil, makes with the direction of H, and it is required to find the magnitude of G, or the magnetic force of the coil alone. On a sheet of paper take any line C O to represent H, the earth's magnetic force. With centre C and radius C O describe an arc of a circle, and mark off a number of degrees on the arc, starting from 0, equal to the angle by which the little magnetic needle at the centre of the coil is deflected from the meridian. Through C and 11 draw a line C P, cutting a line O D at right angles to C 0 in a point P. Then on the same scale on which 0 C represents H, or the earth's magnetic force, O P represents G, or the magnetic force of the current in circle, and we have seen that the value multiplied by 4 and by the radius of the circular coil in centimetres gives the value in amperes of the current flowing in the ci...
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Seller's Description:
Second edition. Hardcover, original blue cloth, index, 210 pp, well illustrated with drawings of electrical experiments, devices and then state of the art machinery. Fair. Cloth soiled and stained, numerous hinge cracks, some of the dye from the cloth has stained the gutters, but that said, a complete, decent enough reading copy. As per title, the principles of electricity presented in an easy to understand format for engineers and electricians. Science; early electricity; antiques; technology.
