Q1) Consider two points charges of the same magnitude but oppsite sign ( +Q and -Q), which are fixed a distance d apart.(adsbygoogle = window.adsbygoogle || []).push({});

A) Can you find a location where a third positive charge Q could be placed so that the net electric force on this third charge is zero?

B) What if the first two charges are both +Q?

The answers for A is : No

The answer for B is : yes, midway between them.

I dont understand how they got this anwer. Is A, no because the oppsite charges cancel each other out?

For B, since all three charges will be positive, how can the net electric charge be 0?

I'm confused...

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Q2) In a capacitor, why is there a distance betwene the two plates? I suppose this is so that an equal and opposite charge can exist? how does having two plates sepreated by a distance create an equal and opp charge in the two plates?

What if there was no distance between them? Then will they have same type of charge?

Thanks much.

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# Homework Help: Net charge & capacitor help.

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