Can you think of any physical examples of electric fields?
What happens to your hair when you take off a wool sweater in the winter?
Or when you hold a balloon with a static charge on it near your head?
This picture shows a girl who is touching a van de Graaf generator. The generator transfers an excess of charge to the girl, including her hair. As the charge builds up on her hair, each strand of hair begins to repel all the rest, and her hair aligns with the electric field lines around her head. What happens to grass seeds floating in oil in the presence of an electric field? This picture shows just this. The grass seeds become polarized and align themselves with the electric field lines created by the two probes. In this case, the probes (one positive and one negative) create a dipole.