Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physics Yr 10 revision > Electricity > Flashcards

Electricity Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

What is electrical current?

A

Electrical current is the flow (movement) of electric charges.

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

what does there have to be for electrical charge to flow?

A

there has to be a source of potential difference and a closed (or complete) circuit.

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

What is electric current measured in?

A

Amperes (A)

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

What is the equation for the flow of charge?

A

The flow of charge (C) = current (A) x time (s)

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

What is the value of the current like in a single closed loop?

A

A current has the same value at every point in a single closed loop.

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

What is the equation for current?

A

current = charge / time

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

Calculate the charge that has flowed past a point in the circuit if the current of 2A has been flowing for 3 seconds…

A
  • Remember the equation for charge.
    Q = I × t
  • Substitute the values in.
    Q = 2 × 3
  • Write the answer, remembering to include an appropriate unit.
    Q = 6 C
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is an electrical insulator?

A

a material which doesn’t allow electric currents (flow of electric charges) to pass through it
-E.g. Glass and Plastic

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

What are electrical conductors?

A

a material that allows electric current (flow of electric charge) to pass through it
-E.g. All metals

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

what does the free electron inside electrical conductors allow?

A

The free electrons inside electrical conductors explain why they can conduct electricity.

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

Why don’t electrical insulators conduct electricity?

A

an electrical insulator has no free electrons so no charges are free to move and carry a current

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

Why do electrical conductors conduct electricity?

A
  • Have lots of charges which are free to move
  • In a metal, the charges that are free to move are electrons
  • the electric current through the metal is the flow o these electrons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What charges are free to move in metals?

A

Electrons

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

The movement of electric ………… is the basis of electrical current

A

charges

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

Current = charge / time

How would you rearrange this equation if you wanted to calculate charge?

A

Charge = current x time

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

An electrical conductor has lots of …………….. that are free to move.

A

charges

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

What is potential difference?

A

Potential difference is the difference in the amount of energy that charge carriers have between two points in a circuit.

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

What is potential difference measured in?

A

Volts (V) -also called voltage

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

What instrument do you use to measure a potential difference?

A

a voltmeter (V)

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

When is energy transferred to the electrical components in a circuit?

A

The energy is transferred to the electrical components in a circuit when the charge carriers pass through them.

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

What is the equation for potential difference?

A

potential difference = current x resistance

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

If voltage is 10V and charge is 2C, what is the energy transferred?

A
  • Remember the equation for voltage
    Voltage = Energy ÷ Charge
  • Rearrange the equation
    Energy = Voltage × Charge
  • Substitute in the numbers
    10V × 2C = 20 J
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

A potential difference of one Volt is equal to one ……….. of energy being used by one ……………. of charge when it flows between two points in a circuit.

A
  • Joule

- Coulomb

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

what does an ammeter measure?

A

The flow of current that passes through it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Ammeters have to connected in ………….. (In the same loop of the circuit) with the electrical component whose current you are measuring.

A
  • series
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What do voltmeters measure?

A

measure potential difference (voltage) between two points in a circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Voltmeters must always be connected in ………….. (on a separate branch of the circuit) with the two points being measured.

A

paralelle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What instrument is used to measure current?

A

an ammeter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

An ammeter must be connected in …………. with the components you want to measure and a voltmeter must be connected in ……………..

A
  • series

- parallel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

The potential difference is the difference in the amount of energy that charge carriers have between two points in a …………… . Potential ……….. (p.d.) is measured in …………… and is also called voltage

A
  • circuit
  • difference
  • Volts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

when charge flows in an electric circuit, the size of the current is a affected by which 2 things?

A
  • The resistance: if the resistance is increased, the current will decrease
  • The potential difference: if the potential difference is increased the current will increase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what is resistance measured in?

A

ohms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What variables affect the size of a current?

A
  • Resistance

- Potential difference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Resistance is a measure of the…

A

difficulty of the flow of current through a component

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what is the equation for resistance? (Ohms law)

A 
R = V/I
resistance = potential difference / current
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

how do we measure resistance across a component? (lamp or resistor)

A

measure the potential difference across the component

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

We calculate potential difference using a …………. and current using an ……………… at the same time.

A
  • voltmeter

- ammeter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what do we use an ammeter to measure?

A

the current flowing through a component

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

how does the length of the wire affect resistance?

A

the longer the wire, the higher the resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

To measure the resistance of a component in a circuit, measure the …………….. difference across the component and the current flowing through the component.

A

-potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what is an ohmic conductor?

A

An Ohmic conductor is a conductor that obeys Ohm’s Law

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

what is the current through an ohmic conductor directly proportional to?

this means that…

A

the potential difference across the resistor

… the resistance remains constant as the current changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what is a conductor in a circuit?

A

a conductor is any electrical component which conducts electricity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

what is the ohms law equation? (Resistance)

A

potential difference = current x resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

In an Ohmic conductor, the resistance…

A

remains constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

How would Ohm’s Law be rearranged to calculate potential difference?

A

potential difference = current x resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

When the potential difference is 10V and the current is 2A, what is the resistance?

A
  • Remember the equation for resistance
    R = V ÷ I
  • Substitute the values in
    R = 10V ÷ 2A
  • Write out answer
    R = 5Ω
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

We can plot a current-voltage graph by varying theacross a circuit component

A
  • potential difference
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

The current-voltage graph for a resistor
has a …………. line obeying …………….. Law:
The slope of the graph is equal to 1/……………….
The constant slope (straight line graph) tells us that the resistance is ……………..

A
  • straight
  • Ohm’s
  • resistance
  • constant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

current = potential difference/……………………….

A

resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

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

A

the line will curve because the temperature and resistance are rising

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What is resistance a measure of?

A

how difficult it is for current to flow through a component

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

To measure resistance you need 3 things:

A
  • an ammeter in series
  • a voltmeter in parallel
  • Ohm’s law
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

The current through an Ohmic ……………… (at a constant temperature) is directly proportional to the …………… difference across the resistor.

A
  • conductor

- potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

the current of an electrical circuit can be calculated using what equation?

A

current (measured in amperes) = potential difference (measured in volts) / resistance (measured in ohms).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

what is current measured in?

A

amperes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

what is potential difference measured in?

A

volts

58
Q

what is resistance measured in?

A

ohms

59
Q

What would you use to measure potential difference across a component?

A

a voltmeter

60
Q

If the resistance is increased, the current will ………………… if the potential difference is kept constant. If the potential difference is increased the current will ………………… if the resistance is kept constant.

A
  • decrease

- increase

61
Q

On a current-voltage graph for a resistor, the slope of the graph is equal to 1/……………..

A

-resistance

62
Q

In an electrical circuit, what makes the current flow?

How?

A

-the energy source (battery or power supply) makes a current flow

It provides electrical energy to a bulb which radiates that energy as light and heat energy.

63
Q

A light bulb is rated at 3V and draws a current of 2A. The bulb is on for 10 seconds. How much electrical work is done on the light bulb?

A

-Remember the equation for electrical work done
E = P × t = I × V × t

-Substitute the values in
E = 2 × 3 × 10

  • Write the answer, remembering to include the appropriate unit
    E = 60 J
64
Q

power is equal to the …………… squared multiplied by the ……………..

A
  • current

- resistance

65
Q

Charge flows from the energy source to the rest of the circuit and its components, like lamps and heaters. The flow of current transfers ……………… from the energy source to the …………………..

A
  • energy

- components

66
Q

in circuit diagrams what do straight lines show?

A

wires connecting the opponents

67
Q

what do circuit diagrams represent?

A

circuits

68
Q

What is the symbol for a motor?

A

a circle with an M in in

69
Q

name two common mistakes when drawing circuits…

A
  • breaks in the lines that you use to represent wires

- wires passing through the components

70
Q

what is a diode?

A

Diodes

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

71
Q

what is a rectifier?

A

a component that turns an alternating current (repeatedly changes direction) into a direct current (One direction)

72
Q

Diodes act as ………………. as they block the ……………… current when it changes direction

A
  • rectifiers

- alternating

73
Q

The current through a diode only flows in …………. direction. In the reverse direction, the resistance is very ………………..

A
  • one

- high

74
Q

what are thermisters and LDRs and what can they be used for?

A

Thermistors and LDRs are devices where resistance changes with temperature or light. They can be used as switches for heaters and lights

75
Q

What is a thermister?

A

a component that’s resistance changes with its temperature

-usually, increasing temperature decreases resistance

76
Q

what can we use a thermister for?

A
  • to turn a heater off when a house reaches certain temperatures
  • fire alarms
77
Q

what are LDRs?

A

a light dependent resistor which changes with light intensity

-usually, increasing light intensity decreases resistance

78
Q

what do we use LDRs for?

A

to switch lights on when it gets dark or to know whether or not a camera phone needs to use “flash”

79
Q

If a thermistor is connected in series with a resistor and battery, what will happen in the circuit when the temperature increases?

A
  • decreased resistance of the thermister

- increased potential difference across the resistor

80
Q

What effect will increased light intensity have on an LDR?

A

decreased resistance

81
Q

A ……………. circuit has all its components connected on the same line as each other.

A

series

82
Q

In a series circuit, the current is the ……………. at all points in the circuit

A

same

83
Q

The charge flows through the circuit like water flows through pipes.
The amount of water entering one end of a pipe is the …………… as the amount leaving the other end

A

same

84
Q

In series circuits, the resistors all oppose the flow of electric current through the circuit. how are their total resistance calculated by?

A

Their total resistance is calculated by adding up the resistances of each individual resistor: R = R1 + R2 + R3 +….

85
Q

What is the resistance of two 10 Ohm resistors in series with three 2 Ohm resistors?

A
  • Remember the formula for the combined resistance of resistors in series
    R = R1 + R2 + R3
  • Substitute the values in
    R = (2 x 10) + (3 x 2)
  • Write the total resistance, remembering to include an appropriate unit
    R = 26 Ohms
86
Q

how is a battery made?

A

by joining cells together

87
Q

how is the potential difference (energy that drives a current to flow through a circuit) of three energy sources in series found?

A

by adding up their individual voltages:

V = V1 + V2 + V3 …

88
Q

the total ………………. of a set of resistors is the sum of the individual …………………….

A
  • resistance

- resistances

89
Q

What is the total potential difference supplied to a circuit when 2 cells, each with a potential difference of 5V, are connected in series?

A
  • Remember the equation for total potential difference
    VTotal = V1 + V2
  • Substitute the values in.
    VTotal = 5 + 5
  • Answer
    VTotal = 10 V
90
Q

Total voltage of energy sources = total …………………… ……………….. across components

A

potential difference

91
Q

What are the key features of a series circuit?

A
  • All components are attached in a row.
  • The current is equal everywhere in the circuit.
  • The voltage across each component is different.
  • The sum of the voltages across each component is the total battery voltage
92
Q

What is the resistance of five 10 Ohm resistors in a series circuit?

A
  • Remember the formula for the combined resistance of resistors in series
    R = R1 + R2 + R3 + R4 + R5
  • Substitute the values in
    R = 5 x 10
  • Write the total resistance, remembering to include an appropriate unit
    50 Ohms
93
Q

How does current change around a series circuit?

A

it doesn’t

94
Q

A ……………… circuit is where there is only one loop of wire, and all the components are on it.

A

series

95
Q

what happens to the current in a series circuit?

A

the current is the same at all points in the circuit

96
Q

In a …………………. circuit, components are connected on separate branches of wires to the energy source

A

parallel

97
Q

In a parallel circuit, components are connected on separate branches of wires to the energy source. The current through the battery is …………………. than the current through each of the individual branches.

A

larger

98
Q

In a ………………. circuit the current through the energy source is equal to the sum of (adding up all of) the currents in the separate branches.

A

parallel

99
Q

In a parallel circuit the current through the energy source is ………………… to the sum of the currents in the separate branches

A

equal

100
Q

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

A

less

101
Q

In the lighting circuit of your house, each lamp is connected to the energy supply in parallel. What are the two main advantages of this?

A
  • Each lamp may be switched on and off separately

- if one lamp stops, current still flows through the others

102
Q

In the lighting circuit of your house, each lamp is connected to the energy supply in ………………..

A

paralelle

103
Q

How do you calculate the total current through the energy source? (in paralle)

A

it is the sum of the currents in the individual branches

104
Q

Resistors in parallel are like water draining out of a bucket with a hole. If a second hole is drilled into the bucket the water (like adding another resistor in parallel) will drain ………….. It does not matter how narrow the second hole is (how high its resistance is), it is always ……………. for water to flow through two holes instead of one.

A
  • faster

- faster

105
Q

is voltage split by the branches in a parallel circuit?

A

no

106
Q

Parallel circuits have two advantages over series circuits. Firstly, each component may be switched on and off ……………. , and secondly, if any one component breaks, current ……………… flow through the other components

A
  • separately

- can

107
Q

what are the 2 types of electrical current?

A
  • direct

- alternating

108
Q

what is the frequency of mains electricity?

A

50 Hz

109
Q

what is the voltage of mains electricity?

A

230 V

110
Q

What does AC stand for and what is it?

A
  • Alternating Current

- When the electric current repeatedly changes direction

111
Q

What does DC stand for and what is it?

A
  • Direct Current

- When the electric current flows in only one direction

112
Q

what colour is the neutral wire?

A

blue

113
Q

what colour is the earth wire?

A

green and yellow stripes

114
Q

what wire is the safety wire which stops the appliance becoming live?

A

the earth wire

115
Q

what is the potential of the earth wire?

A

0V

116
Q

What is the potential of the neutral wire?

A

close to 0V

117
Q

what is the purpose of the neutral wire?

A

completes the circuit and carries current away from the appliance

118
Q

what is the purpose of the earth wire?

A

it is a safety wire and stops the appliance becoming live

119
Q

what colour is the live wire?

A

Brown

120
Q

what is the potential of the live wire?

A

230V

121
Q

what is the purpose of the live wire?

A

provides the alternating potential difference from the mains electricity supply

122
Q

How much energy does a 50W bulb use per second?

A

50J

123
Q

What is the current required by an appliance of power 460W if it is plugged into the mains?

A
  • Remember the equation for power
    P = V × I
  • Rearrange to give current
    I = P ÷ V
  • Remember the potential difference across a mains socket
    V = 230 Volts
  • Substitute the values in.
    I = 460 ÷ 230
  • Answer
    I = 2 A
124
Q

what is the national grid?

A

The National Grid is the network of cables and transformers that connect power stations with houses and shops in the United Kingdom.

125
Q

Earth wires are needed for appliances with what?

A

metal casing

126
Q

A …………. wire can still be dangerous when the mains switch is open (i.e. the plug socket or light switch is turned off).

A

live

127
Q

If you touched the…….. wire, your body would supply a link between the supply and the ground. This is an ………… shock.

A
  • live

- electric

128
Q

What are the advantages of circuit breakers over fuses?

A

Fuses only work once. Once blown, they must be replaced. We can reset circuit breakers. Circuit breakers also break circuits faster than fuses. This reduces the risk of getting an electric shock even more.

129
Q

what are circuit breakers?

A

Circuit breakers are special devices that switch off the flow of current if the current is higher than a certain value

130
Q

what s charge measured in?

A

coulombs

131
Q

how to objects become charged?

A

by losing or gaining electrons (Positively or negatively)

132
Q

opposite charges ………………

A

attract

133
Q

What charge will a material gain if it loses electrons?

A

positive

134
Q

What charge will a material gain if it gains electrons?

A

negative

135
Q

A plastic rod will be charged by rubbing it with a ………….. It will then, attract or ……… other charged objects depending on their charge.

A
  • cloth

- repel

136
Q

Suggest why clothes dried in a tumble drier might stick to each other.

A

The clothes will rub against each other in a tumble drier. This could charge the clothes as electrons are lost when the clothes rub together. Some will lose electrons and become positively charged and others will gain electrons and become negatively charged. The clothes that are oppositely charged will attract each other and stick together.

137
Q

what does static electricity arise?

A

Static electricity arises when electrons transfer from one object to another.

138
Q

When electrons transfer from one object to another, one object becomes …………. and one becomes negative.

A

-positive

139
Q

Charged objects create electric …………. around them

A

fields

140
Q

How can you see electric fields?

A

you can’t

141
Q

what are the electric field lines around tiny positively charged and negatively charged objects called?

A

point charges

Physics Yr 10 revision (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions