Lessons in practical electricity; principles, experiments, and arithmetical problems; over four hundred illustrations; an elementary text book (1909)
Swoope, C. Walton (Coates Walton), d. 1901 · New York, D. Van Nostrand company · leaf 186
g its direction, strengthand pressure. Their construc-tion is based on the principlethat a magnetic needle, or itsequivalent, is deflected whenbrought under the influence ofa magnetic field, such as thatof a wire through which a cur-rent is flowing. A simple gal-vanometer consists essentiallyof a… … Battery Fig. 152.—Simple Galvanometer. instrument is connected in acircuit the presence of the current is shown by the deflectionof the needle. The direction of the current is shown by the 167 168 PRACTICAL ELECTRICITY.
Electricity · Magnetism
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