P4 - Electric Circuits Flashcards
What type of materials can become charged by friction? Why?
Insulators can become charged (with static electricity) as electrons cannot move through them.
E.g Cloth, Polythene rod
What is Static Electricity? How do insulators become charged?
Static electricity is the transfer of electrons from one insulating material to another.
This occurs when 2 insulators are rubbed against one another.
What happens in terms of electrons when a material becomes positively charged?
It LOSES electrons.
What happens in terms of electrons when a material becomes negatively charged?
It GAINS electrons.
What are the 3 rules for Static Electricity?
1) Like charges repel (– or ++)
2) Unlike charges attract (-+ or +-)
3) Only electrons transfer from material to material - NOT PROTONS OR NEUTRONS.
Why do magnets move (repel or attract) based on the charge?
Two charged objects exert a non-contact force on each other.
This force is either repulsion or attraction.
What is the charge of an insulating material determined by?
The charge depends on the material itself.
Why do someone’s hairs stand up when they touch a ‘van der graaf’ generator?
The dome is positively charged (+).
This means that the person touching it becomes positively charged.
Their hairs then stand up because each positively charged hair repels the other hairs.
When a question asks about the motion of a magnet, what 4 things do you comment on?
Whether the object is:
- stationary
- moving at a constant speed
- accelerating
- deccelerating