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.
Question:A student becomes negatively charged because of the friction between her socks and the carpet.
Explain why the friction causes the student to become charged. (2 marks)
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.
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.
Question: A charged object is placed in the electric field around a positively charged dome (Figure 3) . In which location will the object feel the greatest force? Why?
In position Q
Because the electric field is strongest nearer the dome