Let's examine some simple charge distributions to determine the relationship between field strength and the number of field lines. 

Here are five different charge distributions for you to examine.  For each distribution, plot each point charge on your graph paper based on the x and y coordinates listed.  Once you have plotted the points, sketch the trajectory of the field lines throughout the region. 

1) Point Charge:

Charge
( x 1.60 x 10-19 C)
x- coordinate y- coordinate
1 5.00 5.00

2) Dipole: 

Charge
( x 1.60 x 10-19 C)
x- coordinate y- coordinate
1 3.00 5.00
-1 7.00 5.00

3) Quadrapole:

Charge
( x 1.60 x 10-19 C)
x- coordinate y- coordinate
1 3.00 5.00
-1 7.00 5.00
1 5.00 3.00
-1 5.00 7.00

4) Circle:

Charge
( x 1.60 x 10-19 C)
x- coordinate y- coordinate
1 3.00 5.00
1 3.27 6.00
1 4.00 6.73
1 5.00 7.00
1 6.00 6.73
1 6.73 6.00
1 7.00 5.00
1 6.73 4.00
1 6.00 3.27
1 5.00 3.00
1 4.00 3.27
1 3.27 4.00

5) Square:

Charge
( x 1.60 x 10-19 C)
x- coordinate y- coordinate
1 3.00 5.00
1 5.00 7.00
1 7.00 5.00
1 5.00 3.00
-1 5.00 5.00

Further Thinking:  How is the square different without the last point at (5.00, 5.00)?

Remember:  Field lines radiate from positive charges and gravitate toward negative charges.  Also, field lines never cross one another. 

 

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