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Yesterday my teacher was giving us an introduction to the fundamental forces of nature. She asked why opposite charges attract to each other and similar charges repel each other. This question gave me an idea that similar charges may attract to each other. When I discussed this question with my teacher, she said that yes it can happen, if one of the charged bodies is too big in size in comparison of the other. This will happen because the larger body will induce an opposite charge to smaller body and they will start attracting to each other. I am confused with my teacher's explanation and hoping for help here. Please tell me that is it even possible? and if it is, then please elaborate it in an easier way so I can get my mind out of it. Thanks in advance for any help.

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Your teacher might be referring to this article:

Ball (2012), Nature News: Like attracts like?

The key to Lekner’s seemingly bizarre conclusion is that the spheres are electrically conducting. This means that charge can get redistributed non-uniformly on their surfaces. ... When far enough apart, the two spheres do act like more-or-less uniformly charged objects, which repel one another when the charges are alike. But as they get closer, they become polarized: one sphere elicits an image charge in the other by pushing like charge away. At close enough range, the resulting attraction wins out.

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    $\begingroup$ This only works if the charges are unequal or the sizes are unequal. If one of the spheres has a much higher charge density it will polarize the other and that will win out over the other's charge at close range. $\endgroup$ – Kevin Kostlan Oct 13 '16 at 0:39
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If you got point chargers, then there are no way two electrical chargers with the same sign attract each other. But if you do not have point chargers but charged bodies (I mean that have volume), each body will have both positive and negative chargers, but if the body is not electrically neutral it will have more of one of the two types of charge. The charge can move inside the body and because of this you can create a separation of charges if you approach one electrically charged body to another. This is for example the principle of charging by Induction.

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