Electric fields
All charged objects have an Area surrounding an electric charge that may influence other charged particles. around them that determines how they will interact with other charged particles.
A Van de Graaff generator removes electrons to produce a positive charge. A person does not have to touch the Van de Graaff generator to start feeling the effects, as static electricity is a
A person touching the dome of the Van de Graaff generator will also lose electrons and become positively charged. The same will happen to each of their hairs. Since the person, their head, and each of the hair follicles are all positively charged, the hairs will repel from the head and from every other strand causing them to stick out from the head in all directions.
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Electric field shapes
An electric field is a region where Property of matter that causes a force when near another charge. Charge comes in two forms, positive and negative. For example, a negative charge causes a repulsive force on a neighbouring negative charge. experience a A push or a pull. The unit of force is the newton (N)..
Fields are usually shown as diagrams with arrows:
- The direction of the arrow shows the way a positive charge will be pushed.
- The closer together the lines are, the stronger the field and the greater the force experienced by charges in that field. This means that the field is stronger closer to the object.
In a When field lines spread out from a single point. Eg an electron on its own will have a radial field. around a positive charge, other positive charges are repelled away. Therefore, the arrows point away from the central positive charge. This is what happens with a Van de Graaff generator.
However, a negative charge placed in that field would attract the positive charge and feel a force in the opposite direction to the field lines.
The field between two parallel plates, one positive and the other negative, is a When field lines are neat and ordered, usually from one charged plate to another. .
The field lines are straight, parallel and point from positive to negative.
If the field is strong enough, charges can be forced though insulators such as air and a spark will occur. This is what happens during a lightning strike.