Electricity - Electric Charge (Paper 2)

Question 1

what are examples of conducting materials?

Answer 1

• Copper
• Aluminium
• Gold
• Silver

Question 2

what are examples of insulating materials?

Answer 2

• Glass
• Air
• Plastic
• Rubber
• Wood

Question 3

how can you investigate how insulating materials can be charged by friction?

Answer 3

• Hold polythene rod and cloth next to up small pieces of paper one at a time
• Now rub the rod with the cloth
• Again hold close to small pieces of paper
• Turn on a tap so a thin stream of water is flowing
• Hold the rod about 1cm away from the water just below the nozzle
• Repeat with different material rods and cloths

Question 4

how are positive and negative electrostatic charges produced?

Answer 4

by the loss and gain of electrons

Question 5

what is the force between unlike charges and like charges?

Answer 5

unlike - forces of attraction
like - forces of repulsion

Question 6

what materials conduct charge?

Answer 6

conductors

Question 7

what is a static charge?

Answer 7

a charge which builds up in one place and isnt free to move. this normally happens with insulators

Question 8

how can friction cause static electricity?

Answer 8

two insulating materials are rubbed together and electrons are scraped off one onto the other, leaving a positive charge on one and a negative on the other

Question 9

what happens as charge builds up on an isolated object?

Answer 9

the voltage between the object and the earth increases. if it gets large enough electrons can jump the gap between the object and the earth

Question 10

how are electrostatic charges used in printers?

Answer 10

• paper is charged negatively in certain regions
• then positively charged paint droplets are sprayed onto the paper and attracted to the negative regions of the paper giving the desired image.