Relationship between Electric Fields and Distance from point charge?

In summary, the relationship between electric fields and distance from a point charge is an inverse-square relationship, as shown by the equation E=kq/r^2. This means that as the distance from the point charge increases, the electric field decreases at a faster rate, resulting in a curved slope on a 1/r^2 graph. Some individuals may have difficulty understanding this concept, but it is important to remember that the markings on the horizontal axis for a 1/r^2 graph would be 1, 1/4, 1/9, etc, while for a 1/r graph, they would be 1, 1/2, 1/3, etc.
  • #1
dougouk
8
0
Relationship between Electric Fields and Distance from point charge??

Homework Statement


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Homework Equations


E= kq/r^2


The Attempt at a Solution


K so looking at the graph, I noticed that there is a inverse-square relationship between the electric field and the radius/distance.

So I considered that there would have to be a curved slope on a 1/r^2 graph, because the x-axis is squared.

Wouldn't any graph have a curved slope when the x-axis is squared?

For example, a simple equation like y = x^2 results in a curved slope, because the y-axis point is always squared of the x-axis point.

Wouldn't that reasoning work with this?

So my answer is A.



But my friend is saying that the graph would be curved with just 1/r.

And straight with 1/r^2. So her answer is C.

Which is right? Other ppl in my class are also saying that the answer is C as well, but i don't see why.

A lot of people are saying I'm thinking too hard and reaching a wrong conclusion, but they don't know how to explain.

What's wrong with my theory and what's right about my friend's?


Please explain T__T
 
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  • #2


What would the markings look like on the horizontal axis of the 1/r2 graph ?

What would they look like on the 1/r graph?
 
  • #3


SammyS said:
What would the markings look like on the horizontal axis of the 1/r2 graph ?

What would they look like on the 1/r graph?

On the 1/r^2 graph, markings on the x-axis would go

1, 1/4, 1/9, etc

On the 1/r graph, markings would go

1, 1/2, 1/3, etc

This... Does not help me get it.

Please continue though T_T
 

FAQ: Relationship between Electric Fields and Distance from point charge?

1. What is the relationship between electric fields and distance from a point charge?

The electric field strength decreases as the distance from a point charge increases. This relationship is described by the inverse square law, which states that the electric field strength is inversely proportional to the square of the distance from the point charge. This means that the farther away you are from a point charge, the weaker the electric field will be.

2. How is the direction of the electric field determined from a point charge?

The direction of the electric field is determined by the direction in which a positive test charge would move when placed in the electric field. The electric field lines always point away from positive charges and towards negative charges, so the direction of the electric field at any point is tangent to the electric field line passing through that point.

3. Does the distance from a point charge affect the electric field strength in different materials?

Yes, the electric field strength can vary in different materials. This is because the electric field is affected by the material's dielectric constant, which is a measure of how easily a material can be polarized. Materials with higher dielectric constants will have a stronger electric field for a given distance from the point charge, while materials with lower dielectric constants will have a weaker electric field.

4. How does the magnitude of the point charge affect the electric field at different distances?

The magnitude of the point charge directly affects the strength of the electric field at different distances. As the magnitude of the point charge increases, the electric field strength also increases. This means that the electric field will be stronger at any given distance from a larger point charge compared to a smaller point charge.

5. Can the electric field from a point charge be shielded or cancelled out?

Yes, the electric field from a point charge can be shielded or cancelled out by the presence of other charges. This can be achieved by placing a charge with an opposite sign near the point charge, which will create an equal and opposite electric field that cancels out the original electric field. Alternatively, a grounded conductor can shield the electric field by redistributing the charges on its surface in such a way that the electric field inside the conductor is zero.

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