Elementary Electrical Calculations PDF Download

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1909 edition. Excerpt: ...for 1 gram of oxygen the heat is 34,450-f-8 = 4,306 calories, and for 1 gram of water it is 34,450 9 = 3,828 calories. In applying the formula these are the quantities which have to be multiplied by the electro-chemical equivalents of oxygen or water, as the case may be. But the electro-chemical equivalent of oxygen is equal to that of hydrogen multiplied by 8, and that of water is equal to that of hydrogen multiplied by 9. The result of the multiplication of the formula is therefore the same in all the three cases. The electro-chemical equivalent of oxygen is 0.000,082,9; that of water is 0.000,093,3. The formulas for the oxygen and water basis are obtained by substituting the respective factors in (4), giving For oxygen, E = 4.16 X 0.000,083 X 4,306 = 1.487 volts, For water, E = 4.16 X 0.000,093,34 X 3,828 = 1.487 volts, .which are the same as those obtained on the hydrogen basis. The quantity of electricity required for depositing the number of grams of an element equal to its chemical equivalent is the same for all elements. It is 9,580.4 C.G.S. units, or 95,804 coulombs. Thus this quantity of electricity will deposit 107.1 grams of silver, 29.15 grams of nickel, 65.23 grams of gold, 29.52 grams of tin, and so on. The e.m.f. of a couple can be determined from this factor. The energy of a cell is expressible in two ways. It can be expressed in energy units, such as ergs, or in compound electric units, each one the product of a unit of e.m.f. by a unit of quantity. These two must be equal to each other. If the quantity of electricity is known, it is obvious that the quotient of the energy unit divided by the quantity unit will give the e.m.f. Example. Calculate the e.m.f. of the Daniell couple, using the above factor. Solution. 9580.4..