Static electricity (15) Flashcards
State the law of electrostatic
Unlike charges attract
Like charges repel
What is an electric field
An electric field as a region in which an electric charge experiences a force.
What are the things to note about charge
Charge is measured in Coulombs (C). The amount of charge carried by an electron is 1.6 × 10 –19C.
How to draw electric fields
Positive: the arrows go outwards
Negative: the arrows go inwards
What happens when a material gains electrons
When a material gains electrons, it becomes negatively charged. The electrons transferred remain at the surface and are not able to move freely in the material.
Define Electrostatic Charging by Friction
Electrostatic Charging by Friction involves the transfer of electrons from one material to another.
How are insulators charged and discharged
Insulators are charged by friction (e.g. rubbing).
Insulators can be discharge by heating.
Define Electrostatic Charging by Induction
can be discharge by heating. Electrostatic Charging by Induction is a method of charging in which a conductor is charged without contact with the charging body.
What is earthing
Conductors can be discharged by earthing. For positive charged conductor, excess electrons to flow to the charged conductor; for negative charged conductor, electrons to flow away from it.
What are the Hazards of electrostatic charging
1) Lightning
2) Damaging electronic equipment
3)Fires
What are the 3 ways of electrostatic charging
1) friction
2) induction
3) conduction
How is lightning formed
Negative charges accumulate at the bottom of the clouds repelling the electrons near the surface of the Earth.
When the accumulation of charges is large, the air particles nearby are ionised providing a conducting path to the earth.
