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Postby TGTS0907129» Force between point charges

Describe the force between point charges


The quantity of electricity, or charge Q, possessed by a body is simply the aggregate of the amount by which the negative charge exceeds or is less than the positive charges in the body. The term point charge is used to indicate that the charge is not distributed over a large area but rather is concentrated at a specifically located point.

Charles Augustin de Coulomb was the first investigator to place the law of force between electrostatic charges upon experimental basis. His relatively rough experiments established in 1784 the law, now known as Coulomb’s law of electrostatic, that the force F between two point charges Q and Q’ varies directly with each charge, inversely with the square of the distance s between the charges, and is a function of the nature of the medium surrounding the charges. In symbols, Coulomb’s law is

where the dimensional factor k is introduced to take care of the units of F, Q and s and also to provide for the properties of the medium around the charges, insofar as these properties affect the force between the charges. It must be noted that this k is not a dimensionless proportionality constant. The dimensions of k are force × distance2/charge2.
Since, F is always a vector quantity, it must be noted that gives only its magnitude. The direction of the force is always along the line joining Q and Q’.

By TGTT170912123 on 9/21/2015 4:57:44 AM
TGTS0907129 on 9/21/2015 4:51:30 AM

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