Electricity

Question 1

what is electric current. A, Ampere

Answer 1

flow of electrical charge, C, Coulomb

Question 2

are electrons negative

Answer 2

yes

Question 3

chargle flow equation

Answer 3

charge flow + current x resistance

Question 4

what is resistance

Answer 4

measure how it resists (oppose) flow of charge. - ohms, R

Question 5

what is potential difference.

Answer 5

electrical potentail from 1 point to another. V, Volts.

Question 6

increase and higher resistence =

Answer 6

more diffcult charge flow + reduce current.

Question 7

increase and bigger potentail difference =

Answer 7

greater flow of charge + increase current .

Question 8

current through component depends on?

Answer 8

resistance and potential difference

Question 9

what is potentail dfference in parall and series.

Answer 9

parallel= each component same
series=all add up to total amount.

Question 10

ohmic conducter means

Answer 10

current is directly propotional to potentail differenc.e

Question 11

what happens to resisance in fixed resistor.

Answer 11

restaince constant as temperature and current change.

Question 12

what is diode

Answer 12

current flows in 1 direction.

Question 13

what are main 3 wires and colour

Answer 13

live - brown
neutal- blue
earth-green and yellow stripe

Question 14

what are the 3 wires made out

Answer 14

out of copper and layer of coating plastic

Question 15

what is live wire

Answer 15

alternating potentail difference of 230v main supply.
connects to fuse in plug

Question 16

what happens if live wire loose

Answer 16

it will touch the casing and give electric shock as human have 0v making larger current flow of shock.

Question 17

what is neutral wire

Answer 17

completes the cirucit by carry away current. 0V

Question 18

what is earth wire

Answer 18

stops appliances casing from become live 0V.
provides alrnerating path for current to flow away than to use.

Question 19

resistance equation

Answer 19

restaince = potential differnece / current

Question 20

energy transfer, charge flow ewuation

Answer 20

energy transfer = charge flow x potnetial difference

Question 21

why can we use therimsotor as thermostat, exmaple.

Answer 21

because device can turn on/off dependng on temperaure, likewise incubator for premature baiebs.

Question 22

complete this - therimoster
low tempertaure =
high temerpatire=

Answer 22

high resistance beause alot enegry needed to pass through.
low resistance.

Question 23

LDR complete + why
low light, dark =
high light, low =

Answer 23

high resistance cos use energy for current to pass
low resistance cos take litle energy for current to pass thriugh.

Question 24

LDR exmaples

Answer 24

garden light, street light, security

Question 25

what is series cirucit and is it ammeter or volt.

Answer 25

connected one after then other in single loop. with same current each component. - ammeter

Question 26

what happens to resistors in series when add more.

Answer 26

it will increase totola resistance.

Question 27

what happens to potential difference in series

Answer 27

total pd of the power supply is shared between the components.

Question 28

wht is parallel circuit

Answer 28

connected side by side on seperate path, voltmeter.

Question 29

what is the current on parallel circuit

Answer 29

current split proportion for each compoent.

Question 30

what happens to the potentail difference in paralle

Answer 30

thepotentialdifference across each component is the same

Question 31

what happens when adding resistors in parallel

Answer 31

reduces the totol resistance

Question 32

what do LED give off

Answer 32

light and energy effiecnet

Question 33

what is oscilloscope

Answer 33

display how voltage change with time.

Question 34

what is D.C and stand for

Answer 34

direct current of contineous electric current flow 1 direcetion.

Question 35

how does D.C look like on oscilloscope and where supplied in

Answer 35

straight line and cell/batteries.

Question 36

what is A.C and stand for

Answer 36

Alternating current, contineous electric current in reverse.

Question 37

where is A.C supplied in and oscilloscope.

Answer 37

Main supply in National Grid 50Hz, 230V, like up and down repetion.

Question 38

Domestic appliances types

Answer 38

blender, iron, kettle, wash machine, fan, hairdryer

Question 39

Appliances to transfer kinetic and thermal.

Answer 39

Blender (400w) and Fan(20w) by kinetic energy of electric motor as both appliances movement. And thermal by fricition enters.

Question 40

another 1 appliances of transfer kinetic and thermal

Answer 40

Hair dryer and Wash machine, kinetic energy of elctric motor as heat water under motor turns the drum to wash. And thermal as it is both heating element.

Question 41

power, current, resistance equatio

Answer 41

power=(current)2 x reisistance

Question 42

what is a National Grid

Answer 42

sytem of cables and transformer of electric current and voltage for safely arrive to consumer.

Question 43

the bigger distance bwteen power station and home, what happens, and reduce how.

Answer 43

greater energy loss due to resisitance of wire + reduce by build power station near homes and trnasformer.

Question 44

what happens to step-up trnasformer and why.

Answer 44

increase potentail difference because less energy is lost in power cabels. AND decrease current.

Question 45

what happens to step-down transformer and why.

Answer 45

reduce potential difference because for home to use for safety than applaince blow. AND increase current.

Question 46

what is electrically charge

Answer 46

insulating materals rubbed each other

Question 47

what happens when object gain electron AND, object loses electron

Answer 47

Negatively charge AND postive charge

Question 48

what is isolated object

Answer 48

no conducting pathway to earth

Question 49

what happens when there is charge on isolated object

Answer 49

increase potentail difference to cause spark occur

Question 50

what is attraction

Answer 50

2 object carry different charge attratcs.

Question 51

what is repulsion

Answer 51

2 object carry same charge repel.

Question 52

what is electric field

Answer 52

area around charged object that will effect other object

Question 53

when is elctric field strongest AND weakest.

Answer 53

charged object close is strongest AND furhter away charge object is weaknes.

Question 54

what happens when a man touch the dome of generator

Answer 54

man is postive charge because hair goes up as they all repel each other as each hair is postively charged.

Question 55

what happens when rub cloth and plastic rod insulator

Answer 55

electrons move from plastic to cloth

Question 56

why increase p.d and what happens to the current.

Answer 56

Increasing p.d decrease the current. So the smaller current means less energy changed to thermal energy in cabels

Question 57

why national grid system is efficient for energy transfer

Answer 57

It involves high voltage and low current to minmise energy loss of heat in power cables. Then step down transformer reduce voltage and increase current for safety of households, shops.

Question 58

why add resistors in series increases total resistance

Answer 58

adding resistors is increasing resistance, this make it difficult for charge flow for current.

Question 59

How to calculate current when it is mA ——- A

Answer 59

Divide 1000