Lessons in practical electricity; principles, experiments, and arithmetical problems, an elementary text-book . graduatedU tubes with water, close thestop-cocks and connect severalcells in series to posts 1 and 3,when both platinum wires willbe in series and the current thesame through each of the current to flow for ashort time. The column of wa-ter in the open side of the right-hand U tube rises to about doublethe height above the normalposition that the column in the left-hand tube does. Agas under constant pressure expands by a definite fraction ofits volume for a given increas
Lessons in practical electricity; principles, experiments, and arithmetical problems, an elementary text-book . graduatedU tubes with water, close thestop-cocks and connect severalcells in series to posts 1 and 3,when both platinum wires willbe in series and the current thesame through each of the current to flow for ashort time. The column of wa-ter in the open side of the right-hand U tube rises to about doublethe height above the normalposition that the column in the left-hand tube does. Agas under constant pressure expands by a definite fraction ofits volume for a given increase of temperature, consequentlythe air in the bulb, BC, must have been raised to doublethe temperature of that in the bulb, AB, or double thequantity of heat must have been evolved from the wireof twice the length, by the current. The heat generated in anywire is directly proportional to its resistance. In a cell furnish-ing current to an external circuit, twice the heat is evolvedfrom the inside of the cell, if the plates are separated to twicetheir original distance and the current the same in Fig. 237.—Apparatusfor Studyingthe Laws Governing the Heat-ing Effect of an ElectricCurrent. 268 PRACTICAL ELECTRICITY. 2. Heat Developed is Proportional to the Square ofthe Current.—To prove this statement, connect an ammeterin series with either of the bulbs in Fig. 237 by using twoadjacent posts, 1-2 or 2-3. Note the value of the current inamperes, and the corresponding number of cubic centimetersrise of the level of the liquid in the U tube in a given double the current strength, and the liquid in the U tuberises, not to twice the former height, but to four times theformer height in the same time. If the current is tripledthe liquid rises to nine times the height recorded in the firsttest, and when quadrupled to sixteen times the first height,etc. For example, one ampere produces 3 divisions rise ; 2amperes produce 12 divisions rise ( (2x2) X 3) ; 3 amperespr
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Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyo, bookyear1901
