static charge Flashcards
1
Q
describe the production of static electricity by rubbing surfaces
A
- when insulating materials are rubbed against each other, the friction causes electrons to move off one object onto another
- 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
2
Q
what happens when two electrically charged objects are brought close together?
A
- they exert a force on each other
3
Q
which charges move, how are the different charged produced?
A
- ONLY electrons
- positive caused by electrons moving away
- negative caused by more electrons moving on to them
4
Q
describe the production of sparking
A
- a build up of large charge can cause a large potential difference between the object and the earth
- if the potential difference gets large enough, electrons can jump across the gap, causing a spark
5
Q
how does holding a van de graft generator cause funny hair?
A
- as belt moves inside, electrons pass from the top plastic roller onto the belt
- as belt moves over bottom roller, electrons pass off belt and are transferred to earth
- over time the top region becomes positive, building up in the dome
- as you touch the dome, positive charge is transferred, causing your hair to be positive and repel each other, moving apart
6
Q
what would happen if you rubbed a cloth on two pieces of aluminium and why?
A
- nothing would happen
- it is a conductor so electricity can pass through it more easily
