# Homework Help: Electric Field Mapping Lab

1. Feb 11, 2012

### kgal

1. The problem statement, all variables and given/known data

Compute values for the electric field at four different points on the point-line plate. Comment on the validity of your values.

2. Relevant equations

E = F/q
ΔV = ∫E dot ds

3. The attempt at a solution

I have attached 3 electric field maps that I did in the lab and I also have a data table with voltage after the 7 resistors (E1 - E7). I just don't understand how I can calculate the electric field with what I have.

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2. Feb 12, 2012

### Redbelly98

Staff Emeritus
Let's look at this equation:
As an approximation, suppose that E is constant between two consecutive equipotential lines. What does the integral become in that case?

3. Feb 12, 2012

### kgal

E∫ds = E*s...

4. Feb 12, 2012

### Redbelly98

Staff Emeritus
... = ΔV

So to find E ... ?

5. Feb 12, 2012

### kgal

ΔV / Δs ?
Δs should be in meters?

6. Feb 12, 2012

### Redbelly98

Staff Emeritus
Yes.

7. Feb 12, 2012

### kgal

but where does the distance measurement start?
from the point I want to know the electrical field at to where?

8. Feb 13, 2012

### Redbelly98

Staff Emeritus
The distance is measured between two eqipotential lines, along the E-field line. You can take midway between the eqipotentials as the point where you are calculating E.