Two charged spheres are separated by 2 mm. Which of the following would yield the greatest attractive force?
Show Hint
- +2q and -2q
- +2q and +2q
- -2q and -2q
- 1 and -4q
The Correct Option is A
Solution and Explanation
The attractive force between two charged spheres is given by Coulomb's law: \[ F = \frac{k |q_1 q_2|}{r^2} \] where: $k$ is Coulomb's constant, $q_1$ and $q_2$ are the charges, and $r$ is the distance between the charges. The force is greatest when the charges are of opposite signs and the charges are equal, as in the case of $+2q$ and $-2q$.
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Match List - I with List - II:
List - I:
(A) Electric field inside (distance \( r > 0 \) from center) of a uniformly charged spherical shell with surface charge density \( \sigma \), and radius \( R \).
(B) Electric field at distance \( r > 0 \) from a uniformly charged infinite plane sheet with surface charge density \( \sigma \).
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(I) \( \frac{\sigma}{\epsilon_0} \)
(II) \( \frac{\sigma}{2\epsilon_0} \)
(III) 0
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