. A text book of physics, for the use of students of science and engineering . The quadrants Qare supported upon amber blocks A, andtwo of the quadrants are drawn back sothat the paddle inside them can be is the quartz fibre and M the mirror. Kis a conductor through which the paddlecan be charged before any measurementsare made. When in use the paddle hangs symmetri-cally between the quadrants when A, B andC are all at zero potential (Fig. 883). The quadrants AAare connectedtogether by awire so thatthey mustalways havethe same po-tential, whichwe shall callVA ; similarly,BB are con-nect
. A text book of physics, for the use of students of science and engineering . The quadrants Qare supported upon amber blocks A, andtwo of the quadrants are drawn back sothat the paddle inside them can be is the quartz fibre and M the mirror. Kis a conductor through which the paddlecan be charged before any measurementsare made. When in use the paddle hangs symmetri-cally between the quadrants when A, B andC are all at zero potential (Fig. 883). The quadrants AAare connectedtogether by awire so thatthey mustalways havethe same po-tential, whichwe shall callVA ; similarly,BB are con-nected to-gether, andtheir potentialwill be called. Fig. 884.—The quadrant electrometer. 948 MAGNETISM AND ELECTRICITY CHAP. VB. It can then be shown that with these potentials the needle willbe deflected from its zero position by an amount 6, where 0«(v, 2 Vc being the potential of the paddle. In practice Vc is always amuch higher potential than VA or VB, so that when these are small the term ( V Va + Vb is practically constant, and we may write # = K(VA-VB),where K is now a constant, to be determined by experiment. It isthus seen that the deflection is proportional to the difference of potentialbetween the pairs of quadrants. That the needle will undergo a deflection may be seen fromFig. 885. Suppose the paddle to be positively charged and the pair
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishe, booksubjectphysics
