Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

PHYSICS-EVIE > Topic 2-electricity > Flashcards

Topic 2-electricity Flashcards

(65 cards)

Start Studying
1
Q

whats current

A

a flow of electrical charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what does a current rely on to flow round a complete closed circuit

A

potential difference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

whats the unit of current

A

ampere (A)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

when does the current have the same value everywhere

A

in a single closed loop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what does potential difference (voltage) do

A

pushes the charge around

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

whats the unit of potential difference

A

volt(V)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

whats resistance

A

anything that slows the flow down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

whats the unit of resistance

A

ohm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

give the link between current and resistance

A

The greater the resistance across the component the smaller the current that flows

for a given potential difference across the component

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how does a large amount of charge flow around a circuit

A

when a larger CURRENT flows

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what can the resistance of the circuit depend on

A

whether components are series or parallel or the length of wire use in the circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

give examples of ohmic conductors

A

wire or resistors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what thing does the resistance NOT change with the current

A

ohmic conductors

ata a constant temperature the current flowing through ohmic conductor is directly proportional to the potential difference across it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

in what components does the resistance change

A

diodes and filament lamps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what happens when a filament lamp is used in a circuit

A

we the current increases the filament lamp heats up more and the resistance increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what happens with diodes in circuits in terms of resistance

A

they will allow the current to flow in one direction but have a very HIGH resistance if it is reversed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

whats LDR short for

A

light dependent resistor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what’s an ldr

A

a resistor that is dependent on the intensity of light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what does resistance do with ldr

A

in bright light the resistance falls

in darkness the resistance is highest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are LDRs used for

A

automatic night lights outdoor lighting and burglar detectors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What’s the thermistor

A

Temperature dependent resistor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

describe resistance with a thermistor

A

hot conditions -low resistance

cool conditions- resistance goes up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

example of thermisters

A

Car engine temperature sensors and electronic thermorstats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is sensing circuits used for

A

turn on or increase the power to components depending on the conditions that they are in

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
The bigger the components resistance....
The more of the PD it takes
26
describe features of series circuits
* The different components are connected in a line, end to end between the positive and negative of the power supply * if you remove or disconnect one component a circuit is broken and they all stop * The total potential difference of the supply is shared between the various components ( V total = V1+ V2 +.....) *current is the same everywhere (I1=I2=....) * resistance adds up (R total=R1+ R2) * Cell potential differences add up
27
Describe the features of parallel circuits
* each component is separately connected to the negative and positive of the supply * potential difference is the same across all components which means identical bulbs will be at the same brightness (V1=V2=...) * current is shared between branches (I total= I1+ I2+...)
28
what happens when you add resistors in series
The total resistance increases and the current decrease
29
What happens when you add resistors in parallel
Total current increases total resistance decreases
30
What are the two different types of electricity supply
Alternating and direct
31
Main supply is
A/C
32
Battery supply is
DC
33
What does the current to do in AC supplies
It’s constantly changing direction the current is produced by alternating voltages in which the p and n ends keep alternating
34
What is direct current
A current that is always flowing in the same direction created by direct voltage
35
What coats wires
The core of copper and coloured plastic coating
36
Describe the live wire
Brown provides alternative potential difference from mains-supply
37
Describe the neutral wire
Blue complete the circuit and carries away current electricity normally flows in through the livewire and out through the neutral wire
38
describe the earth wire
Green and yellow protects wiring safety stops appliance casing from becoming live doesn’t carry current only when there is a fault
39
What is dangerous about a plug
Any connection between life on earth can be dangerous if the link creates a little resistance path to earth a huge current will flow which could result in a fire electric shock (current flows theough you)
40
what is energy transferred from
cells and other sources
41
What does a moving charge do
Transfers energy because the charge does work against the resistance of the circuit
42
Describe the energy transfer in the kettle
They transfer energy electrically from the mains supply to the thermal energy store of the heating element inside the kettle
43
Describe energy transfers in an electric fan
Energy is transferred electrically from the battery of a handheld fan to the kinetic energy store of the fans motor
44
What does the total energy transferred by an appliance depend on
How long it’s on for and its power
45
What’s the power of an appliance
The energy that are transfers per second
46
water appliances often given
A power rating
47
What is potential difference
Energy transferred per charge passed
48
When energy is transferred what has taken place
Electrical charge goes through a change in potential difference
49
What’s the National Grid
Giant system of cables and Transformers that covers the UK and connect the power stations to consumers
50
How does the National Grid transmit the huge amount of power needed
Boost to the potential difference up really high and keep the current as low as possible increasing the potential difference decreases the current which decreases energy loss by heating the wires and the surroundings which makes it efficient
51
How does the potential difference get to 400,000 V
Transformers are used which step up the potential difference at one end for efficient transmission then bring it down to safe useable levels big pylons with huge insulators are also used
52
What’s static electricity
all about charges which are not free to move | example insulating materials
53
what happens when polythene rod and cloth duster are rubbed together
electrons move from the duster to the rod the rod becomes negatively charged and the duster becomes positively charged
54
what happens if if you rub an acetate plastic rod with a duster
electrons move from the rod to the duster | the duster becomes negatively charged and the rod becomes positively charged
55
what only moves electrons or protons
electrons
56
How was the spark caused by static electricity
as Electric charge builds on an object, the potential difference between the object and the Earth increases if the potential difference gets large enough electrons can jump across the gap between the charged object and the Earth they can also jump to any earth conductor just nearby
57
What’s electrostatic attraction and repulsion
Where opposite electric charges are attracted and same electric charges are repelled
58
when is an electric field created
Around any electrically charged object
59
closer to the object you get...
the stronger the field is and visa versa
60
How do you draw the field lines for an isolated charged sphere
Electric field lines go from positive to negative there always at a right angle to the surface the closer together the lines are the stronger the field is
61
As you increase the distance between the charged objects...
The strength of the field decreases and the force between them get smaller
62
When are sparks caused
When there is a high enough potential difference between a charged object and the Earth
63
What’s ionisation
When the strong electric field causes electrons in the air particles to be removed
64
What does the high potential difference cause
A strong electric field between the charged object and the Earth object
65
What happens when air is ionised
It’s normally an insulator but when it’s ionised it is much more conductive so the current can flow through it

PHYSICS-EVIE (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions