Physics · Electricity · Magnetism / Principles and Exploration
Charges and electric fields — principles and investigation
The electric field tells us the direction of the force that a positive test charge will experience at each point in space. Change the sign, size, and location of the two point charges, move the test charge, and compare the electric fields. This is an experiment that reads the intensity according to the change in distance and the sum of the vectors created by various charges.
How does it work?
At twice the distance, the field is 1/4, and the electric field overlaps as a vector.
E = Σ kq r⃗ / |r⃗|³ · F⃗ = qₜE⃗
Try this investigation
- The arrows on the grid indicate the direction of the field received by the positive test charge. The power of the green dot is reversed according to the sign of the test charge. Arrow lengths are on a logarithmic scale.
- Press the standard conditions button, run it, and record each measurement value.
- The electric field is determined by the source charge. The sign of the test charge only changes the direction of the force.
Interpreting your results
What is the resultant electric field at the exact center between two positive charges of the same size?
If you add vectors of the same size but in opposite directions, you get 0 N/C.
Assumptions and limitations
It is a vacuum model of a stationary point charge. Divergence is prevented by limiting the denominator within the charge center radius of 0.15 m. The numbers in this area are not used to verify the point charge law. The reverse effect of the test charge is omitted.