Q17 of 106 Page 121

Four equal charges 2.0 × 10–6 C each are fixed at the four corners of a square of side 5 cm. Find the Coulomb force experienced by one of the charges due to the rest three.


Given:


Let the force due to charge at corner B, C and D be FB, FC, FD.


Charge at each corner, .


The side of square is.


By Pythagoras theorem,


The length of diagonal .



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Formula used:


By Coulomb’s law, the electric force is given by:



Where ϵ0 is the permittivity of free space


k is the electrostatic constant


q1 and q2 are the magnitude of charges


r is the distance of separation between the charges


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Resolving FC , we get






The net force is:




We know that



Hence, the magnitude of net force is



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