2d Electrical charge

Question 1

What are the two kinds of charge?

Answer 1

• Two kinds of charge - positive and negative
• Like charges repel, opposite charges attract

Question 2

How do you charge objects?

Answer 2

• Insulators can be charged by friction
• The friction causes electrons to transfer from one object to another

Question 3

How can you induce objects?

Answer 3

• Charged objects will also be attracted to neutral ones because they will induce a charge
• eg. charged balloon sticking to wall

Question 4

What happens if there is a build up of charge?

Answer 4

• A build up of charge can cause a spark, which can be a fire hazard

Question 5

How can the risk be reduced?

Answer 5

• The risk can be reduced by connecting the object to the ground with a conductor, this prevents charge from building up

Question 6

What are the uses of static electricity?

Answer 6

• photocopiers and laser printers
• spray painting cars
• filtering factory smoke
• heart defibrillators

Question 7

How does a photocopier work?

Answer 7

• Photocopiers have a rotating drum that is given a positive charge
  This rotates constantly to read large areas
• Light is reflected off the original document to read the information
  Printed dark areas do not reflect well, so the drum stays charged
• Black ink toner is negatively charged, so only attracts to the charged part of the drum when it is sprayed
• Paper is heated to cure the toner and print the page in the same places as the original