static electricity

Question 1

define conductor

Answer 1

material that allows charge to flow through it easily

Question 2

examples of conductors

Answer 2

• silver
• aluminium
• copper
• steel

Question 3

why do metals conduct electricity well

Answer 3

current is the rate of flow of electrons
so the more easily the electrons are able to flow, the better the conductor

Question 4

define insulator

Answer 4

material with no free charge, does not allow flow of charge through them, such as rubber, plastic, wood and glass

Question 5

investigating charging by friction practical

Answer 5

rub both ends of polythene rod with cloth
suspend rod from a stand using a cradle
take an acrylic rod and rub with cloth
bring each end of the acrylic rod to each end of the polythene rod

Question 6

how does an object become charged by friction

Answer 6

• electrons are negatively charged
• theyre transferred from one object to another
• object that gains electrons becomes negatively charged and the other becomes positive

Question 7

how can static electricity be dangerous

Answer 7

electric charge can build up as the fuel flows through the refuelling pipe. this could cause a spark and trigger a explosion

• this is prevented by earthing fuelling truck and aeroplane

Question 8

what could affect the rod experiment

Answer 8

• draft / breeze
• deflection of the rod may be to small

Question 9

what is static electricity

Answer 9

the accumulation of charge on an object

Question 10

how is static electricity used in photocopiers

Answer 10

• image of document projected onto positively charged copying plate
• plate loses charge in the light areas and keeps charge in the dark areas
• negatively charged black toner powder applied to plate and sticks to positive charge
• toner transferred to a new white sheet of paper
• paper is heated to ensure powder sticks

Question 11

how is static electricity used in insecticide sprayers

Answer 11

particles recieve like charge so they repel each other for a larger surface area covered

Question 12

Why does voltage increase with current

Answer 12

With more energy, more energy is transferred to each coulomb of charge hence v = eq

Question 13

Why does the ground become positively charged during a storm

Answer 13

Electrons from the ground are repelled from the surface layers

Question 14

State advantages of a charged nozzle for spray painting

Answer 14

• particles will be positively charged
• like charges repel
• will create a thin and even coat