question_answer

Two charges \[+4e\] and \[+e\]are at a distance\[x\] apart. At what distance, a charge \[q\] must be placed from charge \[+e\]so that it is in equilibrium

A)                    \[x/2\]

B)                                      \[2x/3\]

C)                    \[x/3\]

D)                                      \[x/6\]

Correct Answer: C

Solution :

             For equilibrium of q |F1| = |F2| Which gives \[{{x}_{2}}=\frac{x}{\sqrt{\frac{{{Q}_{1}}}{{{Q}_{2}}}}+1}=\frac{x}{\sqrt{\frac{4e}{e}}+1}=\frac{x}{3}\]