Static Flashcards
How can an insulator be charged by friction
Gains electrons and becomes negatively charged
Name three common electrostatic phenomenons
Shocks from every day objects
lightning
Attraction by induction such as a charge balloon attracted to a ball
Explain electrostatic induction
When insulating materials are rubbed against each other they become electrically charged
The item becomes negatively charged
When it is placed near a neutral object the electrons move slightly further away as the are repelling the - charged object and so surface has a + charge and attracts the - charged object
This is called an INDUCED CHARGE
How does earthing remove excess charge by movement of electrons
A link to the earth means the object is no longer insulated which means any static charge made on the object will instantly flow away making the object neutral again
What are some uses of electrostatic charges in everyday situations
Electrostatic sprayer-
Charges paint by causing transfer of electrons using friction
area to be coated is oppositely charged or earthed
charged particles repel so spread out and attract to part to be painted due to opposite charge
What are the benefits of an electrostatic sprayer in painting or in agriculture
Covering is thin, cheap, even and complete
What are the dangers of every day electrostatic charges
Fuelling cars - if a charge jumps from person to fuel explosion occurs
Why is earthing used
To prevent a dangerous buildup of charge
What are the 3 types of fields
Magnetic gravitational and electrostatic
What is a field
An area in which a noncontact force can be felt by an object
What is an electric field
The electric force per unit of charge felt by an object
How can you tell on a diagram where the electric field is strongest
Where the lines are closest together
How do you draw the direction of a field ?
As if it is a proton
(Towards neg and away from pos)
How does lightning occur
Ice particles in clouds gain electrons from others by rubbing against each other
The bottom of the cloud gains electrons and a negative charge
Electrons in the ground are repelled but the bottom of the cloud
Lighting jumps to the earth as sparks of electrons
