electricity

Question 1

how fuses work

Answer 1

made of thin metal wire
if current too big
wire heats and melts
wire breaks
circuit breaks

Question 2

how damaged insulation is a hazard

Answer 2

if you touch the wire
you can get shocked

Question 3

how overheating cables are a hazard

Answer 3

can cause a fire

Question 4

how damp conditions is a hazard

Answer 4

moisture conducts electricity
can cause fire
or electrocution

Question 5

what is the conducting part of a wire made of

Answer 5

copper

Question 6

how earthing works

Answer 6

earth wire provides low resistance path to earth
causes high current in earth wire
high current causes fuse to melt
cuts electricity supply

Question 7

why a circuit breaker is better for safety

Answer 7

doesn’t melt and break so can be used again
works faster

Question 8

what’s the heating effect

Answer 8

energy transferred
after collisions
between electrons and metal ions
vibrate more
temp increases

Question 9

what’s an alternating current

Answer 9

continuously changing

Question 10

what is a direct current

Answer 10

constantly same direction

Question 11

what happens to current at junctions

Answer 11

it splits

Question 12

what current depends on

Answer 12

voltage
number of components

Question 13

what happens to voltage in series

Answer 13

shared between components

Question 14

advantages of series

Answer 14

controlled by one switch
less wires

Question 15

disadvantages of series

Answer 15

cannot control components separately
if one breaks, all stop

Question 16

advantages of parallel

Answer 16

individually controlled
if one breaks, others still work

Question 17

disadvantages of parallel

Answer 17

more wires

Question 18

what’s a conductor

Answer 18

allows charge to flow

Question 19

what’s an insulator

Answer 19

stops charge to flow

Question 20

why do metals conduct well

Answer 20

delocalised electrons
free to move
current is rate of flow of electrons

Question 21

how does an object get a charge

Answer 21

friction
between insulators
electron transfer
charged

Question 22

what happens to electrons in an acetate rod

Answer 22

they are transferred away

Question 23

what happens to electrons in a polythene rod

Answer 23

they are transferred towards it

Question 24

what is static

Answer 24

a build up of charge on an insulator

Question 25

what is static electricity

Answer 25

when static flows

Question 26

how does a photocopier use static

Answer 26

-document projected
-on positively charged plate
-loses charge in light areas
-keeps positive charge in dark areas
-negative charges toner sticks to positive
- paper placed over
- heat used to stick

Question 27

how fuelling vehicles causes static danger

Answer 27

friction with fuel and pipe
fuel gains charge
spark can cause explosion

Question 28

how earthing prevents static dangers

Answer 28

bond line earths electrons