domestic electricity + energy resources

Question 1

what r the 2 types of current

Answer 1

alternating - this current is constantly changing direction. it i supplied in main electricity
direct current - this current only travels in one direction supplied by cells and batteries

Question 2

how much volts is mains electricity and whats the frequency of uk mains

Answer 2

mains electricity is 230V. the frequency of UK mains electricity is 50Hz

Question 3

what colour is live wire

Answer 3

brown

Question 4

what colour is the fuse

Answer 4

yellow

Question 5

what colour is the earth wire

Answer 5

green and yellow

Question 6

what colour is the neutral wire

Answer 6

blue

Question 7

what are the 3 types of wire

Answer 7

earth.live and neutral

Question 8

whats the live wire

Answer 8

live wire (brown) provides alternating potential difference at 230V

Question 9

whats the neutral wire

Answer 9

neutral wire (blue) - completes the circuit,carrying current away at 0V

Question 10

whats the earth wire

Answer 10

earth wire (green + yellow) - also at 0V and will carry current away from the device in case of a fault

Question 11

theres a fuse between live wire and the live pin if to much current flows what happens

Answer 11

the fuse breaks and stops the flow of current

Question 12

if the electrician touches the live wire he will receive an electric shock explain why

Answer 12

electricians body is 0V
live wire is connected to a metal device at 230V
electrician touches live so large potential difference between him and the live (230V)
current flows though him to ground causing an electric shock

Question 13

how does the earth wire protect u

Answer 13

the earth wire protects you, by carrying this current to “earth” instead of it passing through you

Question 14

when current flows what moves around the circuit

Answer 14

when current flows charges (electrons) move around a circuit

Question 15

whats power

Answer 15

power is the rate of energy transferred in a given period of time

Question 16

whats the national grid

Answer 16

the national grid is a network of cables and transformers which supply the UK with electricity. in order to transmit a certain power, the electricity has a high voltage and a low current. This means less energy is wasted as heat,making the national grid more efficient

Question 17

what are insulators

Answer 17

they dont allow the movement of charge e.g.plastic

Question 18

what do conductors do

Answer 18

allow the movement of charge e.g. metals

Question 19

whats static charge and give example

Answer 19

a buid up of charge that does not move.Can be either positive or negative. Static charge can build up on insulators when they are electrically isolated e.g. when duster is rubbed on rod. Electrons transfer from rod to duster
duster becomes negative rod becomes positive

Question 20

explain what happens when polythene rod is rubbed w duster

Answer 20

when polythene rob is rubbed w duster,electrons are removed leaving the rod positivelt charged. when the rod is moved towards the water, the electrons in the water are attracted towards the edge. now the positive rod attracts the negative side of the water causing it to bend

Question 21

whats an electric field

Answer 21

an electric field is created around any electrically charged object. electric fields are represented by lines

Question 22

whats sparking (static shocks)

Answer 22

when charge builds up an object there is a potential difference between the object and the earth (0 vaults). the large potential difference creates an electric field between the object + the earth . this electric field removes electrons from air molecules,turning the air into a conductor this means the charge can flow through the air

Question 23

whats a transformer

Answer 23

a transformer is a device used in the national grid to change the potential difference of an electrical supply.