Question

two charges are separated by some distance.on what condition the neutral point between them will lie on one side of the charge but not between them​

Answer 1

Given:

• Two charges are separated by some distance.

To Find:

• on what condition the neutral point between them will lie on one side of the charge but not between them​.

Solution:

Let's assume two point charges $Q_1$  and $Q_2$ at distance $x$

Diagram for above condition attached below

We know that,

Zero potential due to a system of two point charge is

• If both charges are like then resultant potential is not zero at any finite point.

• If the charges are unequal and unlike then all such points where resultant potential is zero lies on a closed curve

For internal point

It is assumed that

           $Q_{1} \right |< \left | Q_{2} \right | \right )$  

At  P,

       

            $\frac{Q_{1}}{x_{1}} = \frac{Q_{2}}{\left ( x-x_{1} \right )}$

            $x_{1}= \frac{x}{\left ( \frac{Q_2}{Q_1} +1 \right )}$

Neutral point will be obtained on the side of charge which is smaller in magnitude i.e. it will obtained on the left side of – Q charge and at a distance.

⇒         $t=\frac{R}{\sqrt{\frac{2Q}{Q}}-1}$

⇒          $t =\frac{R}{\sqrt{2}-1}$

 

Neutral point  will obtained on the left side of – Q charge.