# What is the charge density in a one-dimensional electric field?

• PsychonautQQ
In summary, a charge sheet in space has an electric field, but it is not due to the electric field in the x and y directions. The field comes from the z direction.
PsychonautQQ

## Homework Statement

http://grephysics.net/ans/9277/64

I'm confused. How can there be a charge density if the electric field is one dimensional?

Think about charged sheets. What would be the electric field because of a charged sheet that is infinite in size?

so there is an electric field through e_x and e_y but it comes from the e_z field? like it says e_x and e_y are zero but say there was a point (1,0,0) (x,y,z). The "sheet" in the field would make there be an electric field in the x?

I don't know if I'm saying what I'm thinking clearly. I mean it looks the problem states that there is NO E field in the x and y domains, and yet if there is an E field in the Z domain, there can still be an E field in the X and Y because it is a distance r away from the Z. Dig?

What if the sheet of charge is in the x-y plane and is infinite?

PsychonautQQ said:
I don't know if I'm saying what I'm thinking clearly. I mean it looks the problem states that there is NO E field in the x and y domains, and yet if there is an E field in the Z domain, there can still be an E field in the X and Y because it is a distance r away from the Z. Dig?

The "domain" is a region of space. There are no ex and ey domains.
Every point in the domain has coordinates x,y,z. The field is all along the z direction, in every point.
The field lines are all parallel to each other and to the z axis.
Te magnitude of the field changes linearly along the z axis.

Yous just need to see if this field can satisfy Maxwell's equations, and if it can, in what conditions.

Sorry about my previous reply. There was power shortage in my area. Ignore that reply completely. Try calculating the charge density in such a space. It weirdly turns out to be a constant. This means there is a uniform charge distribution throughout the space. I really don't think you can go in the reverse direction (assuming a uniform charge distribution in space and finding the field proportional to z). This seems very weird. The only positive thing here is that there does exist a charge density.

## 1. What is an electric field GRE problem?

An electric field GRE problem is a type of question commonly found in the GRE (Graduate Record Examination) physics section. It involves calculating the electric field at a given point in space, typically caused by a single point charge or a collection of charges.

## 2. How is an electric field calculated?

The electric field is calculated by dividing the force exerted on a test charge by the magnitude of the test charge. Mathematically, it is represented as E = F/q, where E is the electric field, F is the force, and q is the test charge.

## 3. What is the unit of electric field?

The unit of electric field is newtons per coulomb (N/C) in the SI (International System of Units) system.

## 4. What factors affect the strength of an electric field?

The strength of an electric field is affected by the magnitude and distance of the charges creating the field. As the distance between charges increases, the electric field strength decreases. Additionally, the presence of conductors or insulators can also influence the strength of the electric field.

## 5. How can electric field GRE problems be solved?

Electric field GRE problems can be solved by using Coulomb's law, which states that the force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. Other strategies include using vector addition for multiple point charges and integrating to find the electric field for continuous charge distributions.

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