topic 11 static electricity Flashcards
how is a insulator charged with static electricity
through the transfer of electrons - when certain insulators are rubbed together negative charged electrons are rubbed off.
electrons not free to move. builds up.
what is the charge of the two insulators used
one losing electrons is positively charged while one gaining is negatively charged
what charges attract and which repel
oppersite charges attract
like charges repel
How is shock from everday objects caused
as electric charge builds up the potential difference between the object and the earth increases.
If it gets large enough electrons can jump across the gap between the object and earth.
They can also jump to earth conductors (you)
How is lightning caused
build up of charge potential difference increases between earth and cloud. Lightnig jumps down like a really big spark
How does a charged balloon stick to the wall
and comb picking up small pieces of paper.
1) the balloon gains electrons from an insulator (hair) gaining negative charge.
2) The charges on the wall’s surface can move slightly—the balloon’s negative charge repels the wall’s negative charges.
3) Leaves a positive charge on wall attracting the balloon
called ATRACTION BY INDUCTION
How does earthing remove excess charge
Earthing is when you attached a charged object to the earth using a conductor.
The static charge travels into the ground.
The electrons flow down the conductor if charge is negative while electrons flow up the conductor if positively charged.
How is static electricity used in electrostatic sprayers
1) The spray gun is charged which charges the small drops of paint
2) Like charges repel so since each drop same charge spread out in fine, even spray
3) object getting painted gets oppositely charged. It attracts the paint drops.
effects of electrostatic sprayers
Even coat, less paint wasted, no paint shadows
electrostatic uses in the everday
Photocopiers, reduce dust and smoke out of industrial chimneys, electrostatic spraty
dangers of sparking in the refueling
refueling cars- a build of of static electricity could result in a spark which could set alight the fuel
dangers of sparks in airplanes
airplanes- friction between air and plane causes the build up of charge and interfere with communication equipment
dangers of sparks in lightning
lightning- Raindrops and ice bump into each other in rain storm causing top of cloud positively charged and bottom negatively charged causes a big voltage and spark
define electric field
the region where an elecrtic charge experiences a force
how does electric fields explain electrostatic
