question_answer

The distance between the two charges \[25\mu C\] and \[36\mu C\] is \[11cm\] At what point on the line joining the two, the intensity will be zero

A)                    At a distance of \[5\,cm\]from \[25\mu C\]

B)                    At a distance of \[5\,cm\]from \[36\mu C\]

C)                    At a distance of \[10\,cm\]from \[25\mu C\]

D)                    At a distance of \[11\,cm\]from \[36\mu C\]

Correct Answer: A

Solution :

             Suppose electric field is zero at point N in the figure then At \[N\left| {{E}_{1}} \right|=\left| {{E}_{2}} \right|\] which gives \[{{x}_{1}}=\frac{x}{\sqrt{\frac{{{Q}_{2}}}{{{Q}_{1}}}}+1}=\frac{11}{\sqrt{\frac{36}{25}}+1}=5cm\]