Topic 11 - Static Electricity Flashcards

16297831594	how can an insulator become charged using friction?	When you rub an acetate rod with a dry duster some of the electrons move from the acetate onto the duster. Since electrons are negatively charged, the duster gains a negative charge and this leaves the acetate rod with a positive charge.	0
16297853849	like charges	repel	1
16297859200	unlike charges	attract	2
16297890995	static electricity	unbalanced electric charges on the surface or within a material	3
16297931982	charging by induction	1) if a negatively charged balloon is brought near a wall, the negatively charged electrons in the wall are repelled. 2) this causes the surface of the wall to become positively charged. No charges are transferred from the balloon and so we say that the positive charge on the wall has been induced	4
16297979538	shocks from everyday objects	1) when you walk across some types of carpet, you may end up with an unbalanced electric charge 2) if you then touch a conductor, such as a metal tap, electrons will flow between the tap and you and you may feel a small electric shock 3) the electrons flow in whichever direction removes the excess charge and you become discharged or earthed	5
16298007615	lightning	1) static electricity builds up in clouds due to friction between particles of ice or water moved by air currents 2) when the charge is large enough, charged particles travel through the air between the cloud and the earth 3) this causes both lightning and thunder	6
16298040228	lighting conductor	a thick metal rod running down from the top of a building into the earth which discharges the clouds and earths the building	7
16298118539	earthed	connected to earth so that any electrostatic charges can flow away	8
16298110598	dangers of sparking	1) sparks can be dangerous, for example when there is fuel vapour that could ignite 2) this can be a problem for refuelling aircraft, which often become charged when flying through the air - a charge can also build up when fuel flows through a pipe 4) to prevent a spark between a fuel pipe and an aircraft, a 'bonding line' is connected to earth the aircraft before refuelling begins	9
16298289699	uses of electrostatic charges	insecticide sprays - when spraying crops with insecticide, electrodes on the spray nozzle charge the spray droplets as they pass. - the charged droplets spread out because they repel each other and then they are attracted to the plants by induction	10
16298316604	pros of using insecticide spray	- the spray spreads around the plant, even underneath it - less spray falls on the ground - farmers don't need to use as much	11
16298340263	electric field	the space around an object with a charge of static electricity where it can affect other objects	12
16298475272	electric field between parallel plates		13
16298493951	field lines	lines of force that are formed in a magnetic field - never cross - show where the field is strongest - show the direction of the force on a charge in a field - start on a positively charged object	14