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Main » Electricity » Current & Potential Difference » Lesson III.2.3

Electric Potential Difference - Lesson III.2.3

 Key Terms: electric field | electric lines of force | electric potential difference |

An electric field is a region in space where a force is exerted on a positive test charge. The direction of the field is the direction of the force it would exert on a positive test charge. The electric field is radially outward from a positive charge (+q) and radially inward on a negative point charge (-q). Electric lines of force originate at the positive charge and terminate at the negative charge. These lines of force radiate from the charges in three dimensions, and an infinite number of lines could be drawn.

Electric field lines are not always straight. In the case oa an electric dipole the lines are often curved. An electric dipole consists of two separated charges that have opposite signs.

The sign of right electric charge can be changed by the radio button.

The charge can be changed by the scroll bar.

1. As the scrollbar moves left the charge increases/decreases?
2. Describe the electric field when the slider is in the middle and two different charges exists.
3. Describe the electric field when the slider is in the middle and the same charge exists.
Field lines are used to provide a model for the elctric field, they do not really exist. Electric fields do exist and are produced by one or more charges.

 Sharks have electrically sensitive cells that allow them to detect weak electric fields generated by living organisms, specifically their prey.