Determining directions of electric fields

In summary, the direction of electric fields at a particular location is determined by the presence of charges. If the charge is negative, the electric field will point away from the source. If a positive test charge is placed at this location, it will move towards the center. However, the direction of the electrostatic force can also depend on the overall charge distribution. Charge is defined to flow in the direction a positive charge would move. Therefore, if the overall charge is positive, the field will point away from the center and if it is negative, the field will point towards the center. It is important to draw diagrams and understand the charge distribution in order to determine the direction of electric fields and electrostatic forces.
  • #1
Coco12
272
0
How do you determine the direction of fields at the location o the source. if given that the charge is negative, the electrostatic force is away from the source . Do you reason that since the test charge is positive and the charge is negative, it will go towards the center?
 
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  • #3
Sinead302 said:
I don't understand your phrasing.

Direction of charge around a point particle: http://www.pstcc.edu/departments/natural_behavioral_sciences/Web%20Physics/E2020D0101.gif

Direction of charge around two particles of opposing charge: http://upload.wikimedia.org/wikiped...g/300px-VFPt_charges_plus_minus_thumb.svg.png

Does that answer the question?

Not really. Let's say if the electric field is pointing away from the center at a particular location. If a negative charge was placed at this location, what will be the direction of the electric force that it experiences?
 
  • #4
Ah ok, for an electric field to be pointing away from a particular location there needs to be a charge there. If an another charge was simply placed on top of it, it would change the charge at that point, changing the field.
 
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  • #5
Sinead302 said:
Ah ok, for an electric field to be pointing away from a particular location there needs to be a charge there. If an another charge was simply placed on top of it, it would changed the charge at that point, changing the field.


So what would be the direction of the electrostatic force:
Do you judge on the negative charge and assuming that is a positive test charge, it will move towards the center?
 
  • #6
It would be as it is in the point particle diagram. If there's an overall positive charge the field points away from the centre, if there is an overall negative charge it points in towards the centre.

Charge is defined to flow in the direction a positive charge would move.
 
  • #7
Sinead302 said:
It would be as it is in the point particle diagram. If there's an overall positive charge the field points away from the centre, if there is an overall negative charge it points in towards the centre.

Charge is defined to flow in the direction a positive charge would move.

So in my case, it would move towards the center right?
 
  • #8
Also, can you see if you can answer my other question about electric potential difference?? Thank you!
 
  • #9
You haven't said what size your charges are
 
  • #10
Let's say there was an electric field pointing east with a magnitude of 1*10^2 n/c. A negative charge is placed at this location , what will be the direction of the electric force? It would be towards the center right since there is a negative charge?
 
  • #11
I still find your phrasing very vague, I'm sorry.

I'd recommend drawing a diagram.

If I am reading you right then yes. All your field lines will begin pointing East. If a charge is thrown into the middle of that, the field lines will be drawn towards it.
 
  • #12
ImageUploadedByPhysics Forums1386935213.955427.jpg

This is the problem
 
  • #13
I think it's against the rules of this forum for me to just give you the answer.

Do my previous answers make sense to you? Can you apply that to this question?
 
  • #14
I think the way i have been doing it is right. What do u think? I don't need the answer, just whether my theory is right?
 

1. How do you determine the direction of an electric field?

The direction of an electric field can be determined by placing a positive test charge at a given point and observing the direction in which it moves. The direction of the electric field is the same as the direction in which the test charge moves.

2. What is the significance of determining the direction of an electric field?

Knowing the direction of an electric field is important for understanding how electrically charged particles will interact with each other. It also helps in determining the direction of current flow in a circuit.

3. Can the direction of an electric field change?

Yes, the direction of an electric field can change depending on the positions and charges of the particles involved. For example, if a positive charge is placed near a negative charge, the electric field will be directed towards the negative charge.

4. How is the direction of an electric field represented graphically?

The direction of an electric field is represented by lines of force, also known as electric field lines, which point in the direction of the field at each point. The closer the lines are together, the stronger the electric field is at that point.

5. What is the relationship between electric field direction and potential difference?

The direction of an electric field is always perpendicular to the equipotential lines, which represent points of equal potential difference. This means that the electric field will always flow from points of higher potential to points of lower potential.

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