Electric charges create an electric field

• An electric field is created around any electrically charged object

• The closer to the object you get, the stronger the field is

• You can show an electric field around an object using field lines. For example, you can draw the field lines for an isolated, charged sphere:

• Electric field lines go from positive to negative

• They’re always at a right angle to the surface

• The closer together the line, the stronger the field is

Charged objects in a electric field feel a force

• When a charged object is placed in the electric field of another object, it feels a force

• This force causes the attraction or repulsion

• The force is caused by the electric fields of each charged object interacting with each other

• The force on an object is linked to the strength of the electric field it is in

• As you increase the distance between the charged objects, the strength of the field decreases and the force between them gets smaller

Sparking can be explained by electric fields

• Sparks are caused when there is a high enough potential difference between a charged object and the earth

• A high potential difference causes a strong electric field between the charged object and the earthed object

• The strong electric field causes electrons in the air particles to be removed

• Air is normally an insulator, but when it is ionised it is much more conductive, so a current can flow through it. This is the spark