# Electric field E= dV/dS

## Homework Statement

OK we had a lab and the lab was to draw some dots mapping a electric field. I connected the dots, but i have no idea which way the field points and how to calculate the electric field. I think we need to use E= dV/dS , but i have no idea what dS is. Do i just take the distance between the lines? I'm so confuse Please help me

E= dV/dS

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## Answers and Replies

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any1?

I am not sure what your question is asking, are you just trying to figure out which direction the field lines point?

I am not sure what your question is asking, are you just trying to figure out which direction the field lines point?
yes that part of it. My second question is how to i calculate for the value E?

if you place a positive test charge anywhere inside an electric field, the field lines point in the direction this test charge would move.

To calculate E, you can use the equation E=kq/r^2 in the direction of r, where q is the charge of the point, and k is the coulomb constant. if there are more than one point charges, it is just the vector sum of the electric fields generated by each point.

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if you place a positive test charge anywhere inside an electric field, the field lines point in the direction this test charge would move.

To calculate E, you can use the equation E=kq/r^2 in the direction of r, where q is the charge of the point, and k is the coulomb constant. if there are more than one point charges, it is just the vector sum of the electric fields generated by each point.
how do i get r? do i measure the lines?

yes, r is the radius from the point charge to where you are measuring the strength of the electric field.

yes, r is the radius from the point charge to where you are measuring the strength of the electric field.
ty, im going to do it, what is the value if should expect?

That depends on the problem. I don't know what the charges are or where they are located...

SammyS
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Where did the dots come from? What does a row of connected dots represent?

Where did the dots come from? What does a row of connected dots represent?
That the thing I have no idea. All we did was connect a battery and draw on a Electric field mapper. have no idea what the lines mean.

SammyS
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It's pretty tough to analyze data when you have no idea what the data represents.