1 What word describes materials that electricity will pass through?

conductors

2 What word describes materials that electricity cannot pass through?

insulators

3 What components do you need to make a circuit that would make a small torch bulb light up?

battery, connecting wires, lamp; switch is optional

4 What are the two terminals of an electric cell labelled as?

plus and minus

5 In an electric circuit with a battery, which of these materials will conduct: copper, wood, salty water?

copper and salty water

6 Which of these materials are insulators: plastic, metal, air?

plastic and air

7 What component is used to measure current?

ammeter

8 What name is given to the negatively charged subatomic particles that cause an electric current?

electrons

9 Is mains voltage about 15 times, 150 times or 1500 times bigger than the voltage from a battery?

about 150 times

10 If you connect some cells together in series, what is formed?

a battery

11 What is the name of a circuit with one path around it and no branches?

a series circuit

12 What is the name given to a circuit with components in different branches?

a parallel circuit

13 What is the circuit symbol for a lamp?

circle with a cross in it

14 What is the circuit symbol for a cell?

two vertical lines, one longer than the other

15 How can you tell which is the negative terminal of a cell from the circuit symbol?

It is the shorter line.

16 What is the difference between conventional current and the flow of electrons?

Electrons flow from the negative terminal of a cell to the positive terminal, conventional current flows the other way.

17 What unit is current measured in?

amps/amperes

18 What is another term for potential difference?

voltage

19 Which component is used to measure electric current?

an ammeter

20 What are the units for current?

amps or amperes

21 What two conditions are needed to give a current in a circuit?

closed circuit and potential difference

22 Is an ammeter connected in parallel or in series with a component?

series

23 A series circuit has two lamps. When the current through one lamp is 2A, what is the current through the other lamp?

2A

24 A parallel circuit has two lamps in parallel. When the current through each lamp is 2A, what is the current from the battery?

4A

25 Which component is used to measure potential difference?

a voltmeter

26 What are the units for potential difference?

volts

27 Current can be described as the rate of flow of charge. In a metal, what are the charged particles that flow?

electrons

28 In a circuit, energy is transferred to a charge. Where is this energy transferred from?

cell/battery/power supply

29 What is an electric current?

a flow of charge

30 State the unit and the symbol for current.

amp/ampere, A

31 State the unit and the symbol for charge.

coulomb, C

32 Write down the equation relating the total charge that flows to current and time.

Q = I x t

33 State the unit and the symbol for potential difference.

volt, V

34 How many volts is one joule per coulomb?

1V

35 Write down the equation relating the energy transferred in a circuit to the potential difference.

E = Q x V

36 Describe the potential difference between two points in terms of energy transferred.

It is the energy transferred when 1 coulomb of charge moves from one point to the other.

37 State the unit for electrical resistance.

ohm

38 Write down the equation that is used to work out electrical resistance.

R = V / I

39 What unit is used to measure resistance?

ohms

40 What is the symbol for a resistor?

a rectangle

41 What is the symbol for a variable resistor?

a rectangle with an arrow through it

42 What equation connects potential difference, current and resistance?

V = I x R

43 A circuit contains a resistor. If another resistor is added in series with the first, does the total resistance in the circuit increase, decrease or stay the same?

increase

44 A circuit contains a resistor. If another resistor is added in parallel with the first, does the total resistance in the circuit increase, decrease or stay the same?

decrease

45 When resistors are connected in series, how can you calculate the total resistance?

add the resistances together

46 When the potential difference across a fixed resistor is doubled, what happens to the current?

the current doubles

47 What happens to the resistance of a light-dependent resistor LDR when light intensity increases?

It decreases

48 What happens to the resistance of a thermistor when the temperature increases?

it decreases

49 What is the name of a resistor that can be changed by adjusting a dial?

a variable resistor

50 Which component could be used to change the current in a circuit when the temperature changes?

a thermistor

51 Which component could be used to change the current in a circuit when the light intensity changes?

a light-dependent resistor

52 What does a diode do?

conducts electricity in only one direction

53 What happens to the resistance of a filament lamp when the potential difference is increased?

it increases

54 What happens to the resistance of a thermistor when the temperature rises?

it decreases

55 What happens to the resistance of a light-dependent resistor when the light intensity increases?

it decreases

56 What does the graph of current against potential difference look like for a fixed resistor?

straight line through the origin/directly proportional relationship

57 When an electric current passes through a high-resistance wire, what happens to the wire?

it becomes hot

58 How can resistance in the wires in circuits be reduced?

cool the wire / use low-resistance wire / make the wire thicker / make the wires as short as possible

59 Give an example of an appliance that uses the heating effect of a current.

e.g. kettle

60 Give an example of a disadvantage that can result from overheating by an electric current.

e.g. fire, damage to the appliance/wires

61 If the new connecting wires in a house have a lower resistance than the old ones, what effect will this have on daily electricity use?

it will be less

62 When electrons move through a lattice of positive ions, what happens to cause electrical resistance?

collisions

63 When a resistor heats up, what happens to the positive ions to increase resistance?

they vibrate more

64 What is the equation that connects energy transferred to current, potential difference and time?

E = I x V x t, energy transferred = current x potential difference x time

65 H Apart from using lower resistance wires and without changing any components, state one way the resistance in a circuit can be reduced.

thicker wires, cooling

66 H State a second way the resistance in circuits can be reduced.

low resistance materials, thicker wires, or cooling

67 What is the unit for measuring power?

watts

68 Power is the transfer of what each second?

energy

69 Name the unit and give the symbol for power.

watt, W

70 Which is more powerful: kettle A, which boils a mug of water in 1 minute, or kettle B, which boils a mug of water in 2 minutes, or do they both have the same power?

A

71 Write down an equation that links power to energy transferred, E.

or in words

72 Which uses more power: A a 12 V 20 W lamp, or B a 240 V 9 W lamp or do they both use the same power?

A

73 Write down an equation that links power to current and potential difference.

P = I x V or in words

75 What is the mains voltage in the UK?

230 V

76 What is the frequency of the a.c. mains voltage in the UK?

50 Hz

77 What type of energy store does a battery have?

chemical

78 At some time after energy is transferred to an electric toothbrush, in what energy store does the energy end up?

in the thermal store of the surroundings

79 What do the letters d.c. mean?

direct current

80 Describe the way the electrons move in d.c.

in one continuous direction

81 What do the letters a.c. mean?

alternating current

82 Describe the way the electrons move in a.c.

keep reversing direction

83 What are the names of two of the wires in a plug?

two of: live, neutral, earth

84 What is the name of one electrical safety feature found in our homes apart from the earth wire of a plug?

Circuit breaker or fuse

What component of an electrical circuit does this symbol represent?

Open switch

What component of an electrical circuit does this symbol represent?

Closed switch

What component of an electrical circuit does this symbol represent?

Lamp

What component of an electrical circuit does this symbol represent?

Voltmeter

What component of an electrical circuit does this symbol represent?

Ammeter

What component of an electrical circuit does this symbol represent?

Resistor

What component of an electrical circuit does this symbol represent?

LDR

What component of an electrical circuit does this symbol represent?

Thermistor

What component of an electrical circuit does this symbol represent?

Variable Resistor

What component of an electrical circuit does this symbol represent?

Diode

What component of an electrical circuit does this symbol represent?

LED

What component of an electrical circuit does this symbol represent?

Fuse

What component of an electrical circuit does this symbol represent?

Cell

What component of an electrical circuit does this symbol represent?

Battery

Is this an example of a series circuit or a parallel circuit?

Series

Is this an example of a series circuit or a parallel circuit?

Parallel

True/False: You can run your finger all the way through a series circuit from the battery to all the components

True

True/False: You can run your finger all the way through a parallel circuit from the battery to all the components

False

In a series circuit, the voltmeter has to be in series/in parallel around the component

in parallel

What is charge?

The value of electricity flowing through a circuit

What is current?

The flow of electrons

What is potential difference?

What pushes the current around

What is resistance?

Anything that slows down the current

Energy =

charge x potential difference

What is charge measured in?

coulombs

Charge =

Current x time

In a series circuit, electrons all move in the same/different paths

The same

The current in a series circuit changes/stays the same

Stays the same

Current in a parallel circuit is…

split across the branches

What is potential difference measured by?

A voltmeter

In a series circuit, potentiall difference is split/the same across components

Split

In a parallel circuit, potentiall difference is split/the same across components

The same

With resistors in series, the total resistance is…

The resistors added together

With resistors in parallel, the total resistance is…

1/resistance1 + 1/resistance2 etc

Current in a series circuit is…

The same wherever you look at it

What must you do with different potential differences in a series circuit to get the total potential difference?

Add them together

What must you do with different resistances in a series circuit to get the total resistance?

Add them together

In a parallel circuit, the current on each branch is equal to…

the total current

In a parallel circuit, the potential difference in each branch is…

The same

Potential difference =

Current x resistance

In a current/potential difference graph, what is the relationship between a resistor and a constant temperature?

They are directly proportional

What does this current/potential difference graph represent?

A filament bulb

What does this current/potential difference graph represent?

A diode

Diodes let current flow in multiple directions/only let current flow in one direction

Only let current flow in one direction

What is a thermistor used in?

Things like central heating

Thermistors only let _______ flow at certain temperatures

current

What does this graph show about the flow of current from thermistors?

Only lets current flow at certain temperatures - the graph is more steep at high temperatures. As the temperature changes, the resistance changes

What does LDR stand for?

Light Dependant Resistor

What are LDRs used in?

Street lights and security lights

What does this graph show about how resistance flowing through a circuit is affected by light?

Resistance flowing through the circuit changes with the amount of light

Energy =

Current x potential difference x time

Power =

__energy transferred__

time

or

potential difference x current

or

current^{2} x resistance

What is resistance measured in?

Ohms

Mains electricity in the UK is ___V and __Hz

250V and 50Hz

What goes through the fuse?

A very small bit of wire

What happens to the wire in the fuse if too much current goes through it?

It will melt

Why does the wire in the fuse melt if too much current goes through?

This protects the wiring and the appliance if something goes wrong

Name the 3 wires in a plug

Live wire, earth wire and neutral wire

Which wire, neutral, earth or live is a safety feature of plugs?

Earth

What holds wires down in a plug?

Pins

True/False, the cable grip in a wire is a safety feature

True

What does the cable grip do?

Makes sure the wire doesn’t go anywhere

The cable for a plug is ______ incased in plastic

double

Why are plugs cased in plasted?

Safety reasons

What does AC stand for?

Alternating Current

What does DC stand for?

Direct current

Alternating Current comes from…

Mains electricity

Direct current comes from…

Batteries

What is alternating current?

Current that changes - it goes one way or the other way

What is direct current?

Current that just goes one way

What is static electricity?

An object that isn’t normally charged becoming charged

What causes static electricity?

Two insulators rubbing together

What causes two insulators to rub together?

The movement of electrons from one thing to another

What happens when static electricity charges reset?

You get a shock

How do static electricity charges reset?

When you touch something metal

Two charged objects coming together will _____ each other

Repel

A charged object and an oppositely charged object will _______ each other

attract