Electricity Flashcards

1
Q

what does it mean is the charge is fast

A

there is a large electrical current

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

what carries the charge in metals and what is produced

A

the electrons which produce an electric current

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

what is current like in a series circuit

A

the same at all point

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

what is voltage like in a series circuit

A

it is shared between the components

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

advantages and disadvantages of series circuits

A

advantages - requires fewer wires

disadvantages - if a fault occurs the whole circuit stops working

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

what is current like in a parallel circuit

A

the loop adds up to the total current from the supply

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

what is voltage like in parallel circuits

A

the same across each loop

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

advantages and disadvantages of parallel circuits

A

advantages - each loop can be controlled seperatley and if one stops working the rest still work

disadvantages - they are more complicated to construct

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

how do you calculate the total resistance when the resistors are connected

A

adding the value of the individual resistors

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

what is current

A

the rate of flow of charge at a point in the circuit

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

how is current measured and where is it connected

A

with an ammeter in series

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

what is voltage

A

the amount of energy transferred between two points in a circuit

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

what is resistance

A

the opposition to the flow of current

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

what happens to the resistance of the LDR as the light gets brighter

A

the resistance decreases

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

what happens to the resistance of the thermistor as the temperature increases

A

the resistance decreases

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

does a thermistor’s and LDR’sresistance follow a linear pattern?

A

no becuase as the temperature increases the rate of decrease of resistance falls

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

what sizes do fuses come in

A

3A, 5A and 13A

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

what should you do when picking a fuse and why

A

the smallest one which won’t melt
This makes sure that more current doesn’t keep flowing through the circuit and causing more damage to the equipment, or, causing a fire

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

what is circuit breaker

A

an electromagnetic switch which is a safety device

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

what does a circuit breaker do

A

breaks the circuit if the current rises over a certain value

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

what do many appliences have as a insultor

A

plastic casings

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

what does double insulation mean and why does it help with safety

A

all parts of the appliance are insulated in plastic
if a human were to touch the live wire then they could become electrocuted

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

how can electrical energy be supplied

A

by plugging into a main (power supply, battery or cell)

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

what does d.c current stand for

A

direct current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what does a.c current stand for
alternating current
26
what is d.c current
a d.c supply produces a charge through a circuit in one direction
27
what is a.c current
an a.c supply produces a flow of charge that regularley reverses its direction
28
what is static electricity
involves the transfer of electric charges between objects. In electrostatic phenomena, objects become charged through electron transfer by friction, contact, or induction
29
what charges are ALWAYS fixed in static electricity
the positive charges
30
what is an example of static electricity
balloon sticking to the wall
31
what are uses of electrostatic chrages
paint sprayer inkjet printers photocopiers electrostatic filters
32
what are examples of dangers of electrostatic charge
lightning fueling aircraft
33
what can LED's be used for
to indicate the presence of current in a circuit
34
how does current flow
from the positive terminal to the negative terminal of a cell
35
why are metals used as wires
because metal is a good conductor of electrical current
36
why is current conserved at a junction
becuase charge is always conserved
37
what is a fuse
a thin peice of whire which overheats and melts if the current is too high which pretects the circuit
38
what do earth wires do
provide a safe route for current to flow through in case of a short circuit
39
why is double insulation good
it compleately covers the appliances electrical components so the earth wire cannot touch the metal casing
40
what does it mean to charge a body
adding, removing of electrons creating ions
41
what do metals do
conduct and allow electrons to flow through them
42
what do insulators do
slow down the flow of electrons
43
explain an experiment for static electricity between 2 insulators
when 2 insulators are rubbed together the friction causes electrons to move from one to the other and they become charged for example a rod with a cloth
44
what are the 3 wires in a plug
live, neutral and earth
45
how does a current in a resistor result in the electrical transfer of energy and an increase in temperature
Resistance causes transfer of electrical energy to heat energy
46
domestic examples of when a resistor gets hot when a electric current passes through
toasters - contain coils of wire with really high resistance when the current passes through the coil the temperature increases and give off infered radiation Electric kettles- the heating element is placed at the bottom of the kettle The heat is then absorbed by water and distributed throughout the whole liquid by convection
47
what are examples of mains which produce d.c current
cells and batteries
48
what are examples of mains which produce a.c current
Produced by electrical generators i.e. mains electricity
49
what terminals do ac and dc current have
a.c has 2 identical terminals d.c has positive and negative terminals
50
why is parallel more appropiate for domestic lighting
each light switch in you house is part of a branch of a parallel circuit. it just turns one light (or one set of lights) on and off
51
what does the current in series depend on
the applied voltage the number and nature of other components (eg bulbs)
52
current - voltage graphs: what line does a metal fillament lamp have
curve
53
current - voltage graphs: what line does a wire have
straight through zero
54
current - voltage graphs: what line do different resistors have
striaght lines through zero
55
current - voltage graphs: what line does a diode have
striaght to curve
56
why do metal filament lamps have a curve graph
as the temperature of the metal filament increases the resistance increases
57
why does a wire have a straight line through 0
the current through a wire is proportional to voltage (at constant temperature)
58
why do different resistors have a straight line through zero
the current through a resistor is proportional to voltage
59
why do diodes have a straight - curve line
current will only flow in one direction
60
apparatus for investigating current voltage graphs
an ammeter - to measure the current through the component a voltmeter - to measure the voltage across the component a variable resistor - to vary the current through the circuit a power source - to provide a source of potential difference (voltage) wires - to connect the components together in a circuit
61
what is the qualitative effect of changing resistance on the current in a circuit
as you increase the resistance in a circuit, the current will decrease.
62
describe the qualitative variation of resistance of thermistors with temperature
At low temperatures, the resistance of a thermistor is high, and little current can flow through them. At high temperatures, the resistance of a thermistor is low, and more current can flow through them.
63
what is current | in a sloid mettalic conductor
the flow of negitivley charged electrons
64
examples of conductors
metals - copper and silver
65
how are positive and negative electrostatic charges produced on materials by the loss and gain of electrons
The material that gains electrons becomes negatively charged. The material that loses electrons is left with a positive charge
66
what are the forces of attraction and repulsion
attraction between unlike charges repulsion between like charges