Three charges 4q,Q and q are in straight line in the position o,l/2 and l respectively the resultant force on q will be zero

Dear pallavi

two force are acting on q ,one due to 4q and second due to Q

F1 = 1/4∏ε (4q)q/l² 

F2 = 1/4∏ε (Q)q/(l/2)² 

      = 1/4∏ε (4Q)q/l² 

 F1 +F2 =0

1/4∏ε (4q)q/l²   +  1/4∏ε (4Q)q/l²  =0

 Q=-q

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Dear pallavi
two force are acting on q ,one due to 4q and second due to Q
F1 = K(4q)q/1^2
F2 = K(Q)q/(1/2)^2
= K(4Q)q/1
F1 +F2 =0
K(4q)q/1^2 + K(4Q)q/1 =0
Q=-q
Thanks
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