Figure . Coulomb's Law
Mathematically, it is expressed as :
F
--------
d2
Q1Q2
or F = K --------
d2
In S.I. and M.K.S. system, k = 1/4pÎo. Hence the above equation becomes,
F = ----------
4pÎod2
| Now,
1 1 -------- = ------------- = 8.9878 x 109 = 9 x 109 (approx.) 4pÎo 4p x 8.854 x 10-12
|
Hence, Coulomb's Law can be written as
|
Q1Q2 F = 9 x 109 ---------- newton -------------- in a medium Îrd2
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Q1Q2 F = 9 x 109 -------- newton -------------- in air d2 |
One coulomb | Numerical examples | Absolute permittivity | Relative permittivity
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