electricity

Question 1

what is electrical current

Answer 1

the flow of electrons

Question 2

units of current

Answer 2

amp

Question 3

what is an insulator

Answer 3

a material that doesn’t allow electric currents

Question 4

what is a conductor

Answer 4

a material that allows electric currents to pass through it

Question 5

why can conductors conduct electricity

Answer 5

it has electrons that are free to move

Question 6

what is potential difference

Answer 6

the difference of electrical potential between two points

Question 7

unit of pot diff

Answer 7

volts

Question 8

where do you put an ammeter

Answer 8

connected in series

Question 9

where do you put a voltmeter

Answer 9

connected in paralell

Question 10

what is resistance

Answer 10

a measure of how difficult it is for current to flow through a component.

Question 11

how can the size of the current be affected

Answer 11

resistance
potential diff

Question 12

unit of resistance

Answer 12

ohms

Question 13

how can resistance be affected

Answer 13

length of wire

Question 14

what is the relationship between current and voltage in a resistor

Answer 14

directly proportional

Question 15

What effect will increasing the current through a filament bulb have on the graph

Answer 15

it will curve because the temp and resistance are rising

Question 16

what is a diode

Answer 16

a component that only allows current to flow through it in one direction.

Question 17

what is a rectifier

Answer 17

a component that turns an alternating current into a direct current

Question 18

what is a thermistor

Answer 18

a component where resistance changes with its temperature.

Question 19

what is an ldr

Answer 19

resistance changes with light intensity.

Question 20

what happens when you increase the temp in a thermistor

Answer 20

resistance decreases

Question 21

what happens when you increase the light intensity

Answer 21

resistance decreases

Question 22

what is ohms law

Answer 22

The current through an ohmic conductor (at a constant temperature) is directly proportional to the potential difference across the resistor.

Question 23

in an ohmic conductor the resistance

Answer 23

remains constant

Question 24

current between components in series are

Answer 24

the same

Question 25

resistance between components in series are

Answer 25

added up

Question 26

how to find the total potential diff in series

Answer 26

add up the individual voltages of the cells

Question 27

How are the voltages across components related to the battery voltage?

Answer 27

they sum together to give the battery voltage

Question 28

how is current displayed in a parallel circuit

Answer 28

split between the branches

Question 29

resistance in a parallel circuit is

Answer 29

The combined resistance of two resistors in parallel is less than the resistance of either of the two resistors by themselves.

Question 30

how to work out the reciprocal of the total resistance

Answer 30

the sum of the reciprocals of the individual resistances

Question 31

how is voltage shown in a series circuit

Answer 31

the same

Question 32

what is mains electricity

Answer 32

50hz and 230v

Question 33

what is the brown wire

Answer 33

live wire

Question 34

what is the live wire

Answer 34

provides a current

Question 35

what is the blue wire

Answer 35

neutral wire

Question 36

what does the neutral wire do

Answer 36

completes the circuit

Question 37

what is the yellow and green

Answer 37

earth wire

Question 38

what is the earth wire

Answer 38

stops the appliance becoming live and has 0V

Question 39

what is the national grid

Answer 39

the network of cables and transformers that connect power stations with houses and shops in the United Kingdom

Question 40

what are step up transformers

Answer 40

increase the potential difference to 400,000 Volts.

Question 41

why are step up transformers used

Answer 41

this reduces the current and how much heat is lost increases efficiency

Question 42

what are step down transformers

Answer 42

gets the electricity down to a safer voltage

Question 43

what is a fuse

Answer 43

when the current gets too high the fuse melts and breaks the circuit

Question 44

what happens when a case becomes live

Answer 44

it needs earthing

Question 45

what can a charged rod do

Answer 45

attract a gentle stream of watere

Question 46

what is static electricity

Answer 46

electrons transfer from one object to another

Question 47

what does a charge object create

Answer 47

an electric field

Question 48

what way do the electric field lines do on a positive

Answer 48

away

Question 49

what ways effect the electric field

Answer 49

closer the object is to a charged object higher the charge of the object