True or False? A negatively charged object has an excess of electrons. The positive charges move in...
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![Page 1: True or False? A negatively charged object has an excess of electrons. The positive charges move in a metal to balance the movement of free electrons.](https://reader035.fdocuments.us/reader035/viewer/2022072015/56649ebb5503460f94bc34e7/html5/thumbnails/1.jpg)
True or False?
• A negatively charged object has an excess of electrons.
• The positive charges move in a metal to balance the movement of free electrons.
• The amount of charge depends on the mass of an object.
![Page 2: True or False? A negatively charged object has an excess of electrons. The positive charges move in a metal to balance the movement of free electrons.](https://reader035.fdocuments.us/reader035/viewer/2022072015/56649ebb5503460f94bc34e7/html5/thumbnails/2.jpg)
True or False?• Uncharged materials cannot be attracted by
charged materials.
• The atoms in the metal plate of an electroscope rearrenge to form eletric dipoles when a charge approaches.
• The charges collected by the top comb of a Van Der Graaf generator can distribute around the metal dome because this is connected with the comb by metal connections.
![Page 3: True or False? A negatively charged object has an excess of electrons. The positive charges move in a metal to balance the movement of free electrons.](https://reader035.fdocuments.us/reader035/viewer/2022072015/56649ebb5503460f94bc34e7/html5/thumbnails/3.jpg)
Applied Electrostatics
![Page 4: True or False? A negatively charged object has an excess of electrons. The positive charges move in a metal to balance the movement of free electrons.](https://reader035.fdocuments.us/reader035/viewer/2022072015/56649ebb5503460f94bc34e7/html5/thumbnails/4.jpg)
Inkjet printer
• The ink droplets are charged as they thrust against the nozzle
• The droplets are deflected as they pass between two electrically charged plates
• The amount of charge, i.e. the size and direction of the voltage, on the plates keeps changing to drive each droplet to the right place on your paper
• What charge will the droplets deflected upwardly have? Why?They will be negatively charged, because -ve charges are attracted by the positive plate at the top and repelled by the negative plate at the bottom.
A4 paper
Fine nozzle
Positive plate
Negative plate
![Page 5: True or False? A negatively charged object has an excess of electrons. The positive charges move in a metal to balance the movement of free electrons.](https://reader035.fdocuments.us/reader035/viewer/2022072015/56649ebb5503460f94bc34e7/html5/thumbnails/5.jpg)
Photocopier
• The metal plate is electrically charged and the image to photocopy is projected onto it
• The lighter parts of your image cause the light to shine on the plate, so that the charge leaks away
• The charged bits attract black powder which deposits on the paper
• The paper is heated by the heated rolls, so that the powder sticks on it
Negative plate
Toner (black powder)
Heated rollers
![Page 6: True or False? A negatively charged object has an excess of electrons. The positive charges move in a metal to balance the movement of free electrons.](https://reader035.fdocuments.us/reader035/viewer/2022072015/56649ebb5503460f94bc34e7/html5/thumbnails/6.jpg)
Spray painting
• The spray nozzle is connected to a positive terminal, so the paint droplets become positively charged
• This makes them repel each other, so the paint spreads out
• The object you are painting is connected to the earth (or to a negative terminal)
• This attracts the paint, giving an even coverage
Negative chargePositive nozzle