Static Electricity Flashcards
What can happen when insulating materials are
rubbed together?
They can become (statically) electrically charged.
Why can insulators become electrically charged
when rubbed together?
● Electrons transfer from one material onto the other
● The material gaining electrons becomes negatively
charged
● The material losing electrons becomes equally
positively charged
What would happen when two electrically charged
objects are brought close together?
They exert a force on each other
What happens when two identically charged objects
are brought close together?
They exert a repulsive force on each
other and repel
What happens when two oppositely charged objects
are brought close together?
They exert an attractive force on each
other and attract
Give an example of a non-contact force
The repulsive or attractive force acting
between two electrically charged objects
Why do we feel an electric shock?
● When an object builds up an electrostatic charge, it
needs to be ‘earthed’ via a conductor.
● Electrons flow to/from the earth to balance the charge.
● This can also occur if you touch a charged object whilst
you are earthed.
● If earthing occurs through a person/animal, it causes an
electric shock
Why does lightning occur?
● Clouds can build up an electrostatic charge.
● When this charge becomes large enough, the clouds discharge via the air to the earth.
● This is known as lightning
Why does a charged balloon stick to the wall?
When a positively charged balloon is placed
next to a wall the positive charges near the balloon get repelled to other parts of the wall. This leaves an area of the wall with a
negative charge, which attracts the positively
charged balloon towards the wall, making the
balloon stick.
(The inverse occurs with a negatively charged balloon).
How does earthing remove excess charge?
It provides a path with a low resistance
for the electrons to flow either from the
device or towards the device to reduce
the charge build up
How does static electricity cause danger when
fuelling cars?
● Static charge can build up due to the friction between the pipes and the fuel
● When the charge builds up, a spark may be discharged
● The spark could start a fire if it reacts with the flammable fuel
● This is resolved by earthing the vehicle and pump
What is an electric field?
A region where an electric charge will
experience a non-contact force.
What direction do the field lines in an electric field point?
In the direction that a positive charge would move (experience a force). Away from positive.
Describe the appearance of electric field lines in a
parallel field.
Straight lines, which are parallel to each other and point from the positive plate to the negative plate. At the edges, the lines are partially curved.
Which field is the stronger field?
The field lines being closer together shows a stronger field
