Static Electricity (10) Flashcards
Static electricity is all about ___________ which are not free to move. This causes them to build up in one place and often ends with a _________ or a shock when they do finally _________
Charges
Spark
Move
Materials that are electrical conductors conduct charge easily - a ___________ can flow through them. They’re usually _________
Current
Metals
Electrical ________________ don’t conduct charge very well - so a _________ can’t flow. Examples include ____________
Insulators
Charge
Rubber/plastic
Build up of static is caused by ____________
Friction
When two ______________ materials are rubbed together, electrons will be scraped off one and dumped onto the other. This’ll leave a ___________ electrostatic charge on one and a negative electrostatic charge on the other. Which way the electrons are transferred depends on the two ____________ involved. Electrically charged objects ___________ small objects near them.
Insulating
Positive
Materials
Attract
With a polythene rod, electrons move ______ the duster ______ the rod
From the duster to the rod
Which charges move
Electrons (negative electrons)
Positive charges don’t
How is a positive static charge caused
By the movement of electrons moving somewhere else
As charge builds up so does the ___________ - causing ___________
Voltage
Sparks
The greater the charge on an isolated object, the greater the __________ between it and the earth. If the voltage gets big enough there’s a _________ which jumps across the gap
Voltage
Spark
You can test whether an object is charged, and whether the charge is positive or negative by looking for _____________ or ____________
Attraction
Repulsion
Like charges ________
Repel
Opposite charges __________
Attract
Experiment demonstrating electrostatic charge
Suspending a charged rod
1) Suspend a charged rod on a thread
2) Bring another rod towards it and see if it is attracted or repulsed
3) If there is an attraction then the test rod has the opposite charge to the suspended rod.
If there is a repulsion, then the test rod has the same charge as the suspended rod
A Van de Graaf generator is used to demonstrate _____________ charges.
Electrostatic
If you stand on an insulated chair and place your hands on a Van de Graaf, _____________ will move between your body and the dome, giving your body a _________.
The human body __________ charge, and like charges ___________, so the charges will spread out as much as possible. The charge is so strong, it will make your hairs ________ each other and stand on end
Electrons Charge Conducts Repel Repel
How is static electricity used in a printer
1) Tiny droplets of ink are forced out of a fine nozzle, making them electrically charged
2) The droplets are deflected as they pass between two metal plates. A voltage is applied to the plates - one is negative and the other is positive
3) The droplets are attracted to the plate of the opposite charge and repelled from the plat with the same charge
4) The size and direction of the voltage across each plate changes so each droplet is deflected to hit a different place on the paper
5) Loads of tiny dots make out the piece of paper
How is static electricity used in a photocopier
1) The image plate is positively charged. An image of what you’re copying is projected onto it
2) Whiter bits of what you’re copying make light fall on the plate and the charge leaks away in those places
3) The charged bits attract negatively charged black powder, which is transferred onto positively charged paper.
4) The paper is heated so the powder sticks
5) Done
When clothes are dragged over your head, ___________ get scraped off, leaving static charges on both parts leading to ____________ and little sparks as the charges rearrange themselves
Electrons
Attraction
How is lightening caused
Rain drops and ice bump together inside storm clouds, knocking off electrons and leaving the top of the cloud positively charged and the bottom of the cloud negative. This creates huge voltage and a big spark
Lightening is caused by rain drops and ice bumping together inside storm clouds, knocking off ___________ and leaving the top of the cloud ______________ charged and the bottom of the cloud ____________. This creates huge ____________ and a big spark.
Electrons
Positively
Negative
Voltage
As fuel flows out of a filler pipe, static can build up. This can easily lead to a ________ and in dusty or fumy places - BOOM. The solution: make the nozzles out of __________ so that the charge is ____________ away, instead of building up. It’s also good to have earthing straps between the fuel tank and the fuel pipe.
Metal
Spark
Conducted
1) Tiny droplets of ink are forced out of a fine nozzle, making them (1)____________ charged
2) The droplets are deflected as they pass between two (2)________ plates. A (3)__________is applied to the plates - one is (4)_________ and the other is (5)___________
3) The droplets are attracted to the plate of the (6)____________ charge and repelled from the plate with the same (7)_________
4) The size and direction of the (8)_________ across each plate changes so each droplet is (9)____________ to hit a different place on the paper
5) Loads of tiny dots make out the piece of (10)________.
- Electrically
- Metal
- Voltage
- Negative
- Positive
- Opposite
- Charge
- Voltage
- Deflected
- Paper
1) In a photocopier the image plate is _____________ charged. An image of what you’re copying is projected onto it.
2) Whiter bits of what you’re copying make _________ fall on the plate and the charge leaks away in those places
3) The charged bits attract ___________ charged black powder, which is transferred onto ____________ charged paper.
4) The paper is __________ so the powder sticks
5) Done
Positively Light Negatively Positively Heated
Lightning always chooses the __________ path to get to the ground - even if that means going through tall buildings and trees
Easiest
