Static (Triple Physics Only)

When certain insulating materials are rubbed against each other they become electrically charged. Negatively charged electrons are rubbed off one material and on to the other. The material that gains electrons becomes negatively charged. The material that loses electrons is left with an equal positive charge.

When two electrically charged objects are brought close together they exert a force on each other.

Two objects that carry the same type of charge repel.

Two objects that carry different types of charge attract.

transfer of electrons

from the carpet to the student

Attraction and repulsion between two charged objects are examples of non-contact force.

An electric field is a region around a charged object where another charged object will feel a force.

A charged object creates an electric field around itself. The electric field is strongest close to the charged object. The further away from the charged object, the weaker the field.

A second charged object placed in the field experiences a force. The force gets stronger as the distance between the objects decreases.

Direction of electric field round a point charge
The arrows show the direction of the electric field round a point charge

Charge can have enough energy to jump to another object when enough of it builds up on it. The sparks that happen can cause a static shock or even a fire.

In position Q

Because the electric field is strongest nearer the dome