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प्रश्न
Plot a graph showing the variation of coulomb force (F) versus ,`(1/r^2)` where r is the distance between the two charges of each pair of charges: (1 μC, 2 μC) and (2 μC, − 3 μC). Interpret the graphs obtained.
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उत्तर
I am answering it as Graph between F vs `1/r^2`for (1μC, 2μC)
For (2μC − 3μC)
Interpretation
Graphs show that `F ∝ 1/r^2`
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Slope gives a constant value and depends only on nature of charges and medium.
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Ist graph is for repulsive force in Ist quadrant and IInd graph is for attractive force in IVth quadrant i.e., F > 0 and F < 0 respectively.
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F = `(Qq)/r^2 hatr`
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The number [3] actually arises from the speed of light in vaccum which is now taken to be exactly given by c = 2.99792458 × 108 m/s. An approximate value of c then is c = [3] × 108 m/s.
(i) Show that the coloumb law in cgs units yields
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or, `1/(4pi ∈_0) = (2.99792458)^2 xx 10^9 (Nm^2)/C^2` (exactly).
