Question

The figure below shows the electric field lines for two charged particles separated by a small distance.


(a) Determine the ratio q1/q2.

The figure below shows the electric field lines for two charged particles separated by a small distance.(a) Determine the ratio q1/q2. I have tried 1/2, 1/3, 0.333 but those are not the answers please help!

I have tried 1/2, 1/3, 0.333 but those are not the answers please help!

Answer 1

Concepts and reason

The concepts used to solve this problem is electric field lines.

First, calculate the charge on ${q_1}$ by counting the total number of electric field lines in coming from ${q_2}$ . After that calculate the charge ${q_2}$ by counting the total number of outgoing electric field lines from ${q_2}$ .

Fundamentals

Electric field lines never intersect each other. Electric field lines always begin on a positive charge and end on a negative charge.

The total number of electric field lines living a positive charge or entering a negative charge is directly proportional to the magnitude of charge.

Calculate the amount of charge on ${q_1}$ .

The electric field lines end at ${q_1}$ it means the charge on ${q_1}$ is negative and the total number of line end at ${q_1}$ is $6$ .

Then, the charge on ${q_1}$ is,

${q_1} = - 6{\rm{ unit}}$

Calculate the amount of charge on ${q_2}$ .

The electric field lines start from ${q_2}$ it means the charge on ${q_2}$ is positive and the total number of the line beginning from ${q_2}$ are $6$ .

Then, the charge on ${q_2}$ is,

${q_2} = + 18{\rm{ unit}}$

Now calculate the ratio of $\frac{{{q_1}}}{{{q_2}}}$ .

Substitute $- 6{\rm{ unit}}$ for ${q_1}$ and $+ 18{\rm{ unit}}$ for ${q_2}$ .

$\begin{array}{c}\\\frac{{{q_1}}}{{{q_2}}} = \frac{{ - 6{\rm{ unit}}}}{{ + 18{\rm{ unit}}}}\\\\ = - \frac{1}{3}\\\end{array}$

Ans:

The ratio of $\frac{{{q_1}}}{{{q_2}}}$ is $- \frac{1}{3}$ .