Explanation Electrostatic induction

using electroscope show electrostatic induction. device has leaves/needle become charged when introducing charged rod it. leaves bend leave/needle, , stronger static introduced, more bending occurs.



demonstration of induction, in 1870s. positive terminal of electrostatic machine (right) placed near uncharged brass cylinder (left), causing left end acquire positive charge , right acquire negative charge. small pith ball electroscopes hanging bottom show charge concentrated @ ends.

a normal uncharged piece of matter has equal numbers of positive , negative electric charges in each part of it, located close together, no part of has net electric charge. positive charges atoms nuclei bound structure of matter , not free move. negative charges atoms electrons. in electrically conductive objects such metals, of electrons able move freely in object.

when charged object brought near uncharged, electrically conducting object, such piece of metal, force of nearby charge due coulomb s law causes separation of these internal charges. example, if positive charge brought near object (see picture @ right), electrons in metal attracted toward , move side of object facing it. when electrons move out of area, leave unbalanced positive charge due nuclei. results in region of negative charge on object nearest external charge, , region of positive charge on part away it. these called induced charges. if external charge negative, polarity of charged regions reversed.

since process redistribution of charges in object, doesn t change total charge on object; still has no net charge. induction effect reversible; if nearby charge removed, attraction between positive , negative internal charges causes them intermingle again.