1

Table of Contents
1.ELECTRICAL QUANTITIES ............................................................................................................................... 1
I .DESCRIBE AN EXPERIMENT TO DISTINGUISH BETWEEN ELECTRICAL CONDUCTORS AND INSULATORS ....................................... 2
II. DESCRIBE SIMPLE ELECTRIC FIELD PATTERNS, INCLUDING THE DIRECTION OF THE FIELD: .................................................. 13
(A) AROUND A POINT CHARGE ............................................................................................................................ 13
(B) AROUND A CHARGED CONDUCTING SPHERE ....................................................................................................... 13
(C) BETWEEN TWO OPPOSITELY CHARGED PARALLEL CONDUCTING PLATES (END EFFECTS WILL NOT BE EXAMINED) ............... 13
APPLICATIONS OF ELECTROSTATICS ...................................................................................................................... 16
III CONDUCTION IN METALS IN TERMS OF THE MOVEMENT OF FREE ELECTRONS ............................................................... 18
(IV) ELECTRIC CURRENT: ................................................................................................................................... 19
V. ELECTROMOTIVE FORCE AND POTENTIAL DIFFERENCE ........................................................................................... 20
6.RESISTANCE ............................................................................................................................................... 23
6.1VI graphs .......................................................................................................................................... 23
2.PRACTICAL ELECTRICITY ................................................................................................................. 30
I. USES OF ELECTRICITY..................................................................................................................................... 30
II. STATE COMMON USES OF ELECTRICITY .............................................................................................................. 31
SWITCHES,FUSES AND CIRCUIT BREAKERS: ............................................................................................................. 33
ELECTRIC CIRCUITS ......................................................................................................................................... 41
I .SERIES AND PARALLEL CIRCUITS......................................................................................................................... 41
CALCULATE CURRENT, VOLTAGE AND RESISTANCE IN PARTS OF A CIRCUIT OR IN THE WHOLE CIRCUIT ..................................... 57
VARIABLE RESISTORS,LDR AND THERMISTOR .............................................................................................. 59
THEORY/STRUCTURED QUESTIONS ...................................................................................................................... 60

1.Electrical quantities
Q1
 2

5054/12/M/J/22 /q30

i.Describe an experiment to distinguish between electrical conductors and insulators

Q2

5054/12/O/N/19/q30
 3

Q3

5054/11/M/J/22/q28

Q4
 4

5054/11/M/J/20/q34

Q5.
 5

5054/21/O/N/21/q5

Q6. Electrostatic charges can be placed on objects by friction.

(a) State the name of the charged particle that is transferred from one object to another in this
process.
......................................................................................................................................[1]
(b) Fig. 5.1 shows petrol (gasolene) being pumped into a can. Electrostatic charges build up
on the petrol and the pipe.

(i) Explain why this is dangerous.

...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...............................................................................................................................[2]
 6

(ii) State what can be done to stop the electrostatic charge building up in this way.
...................................................................................................................................
...............................................................................................................................[1]
5054/02/M/J/03/q5

Q7. Fig. 7.1 shows two charged metal spheres. One sphere has a positive charge and the other
sphere has a negative charge.

(a) On Fig. 7.1, draw the electric field between the two spheres. [2]
(b) The negative charge on the sphere is removed and a wire is used to connect the positive
sphere to earth. The charge on the positive sphere decreases from 4.8 × 10^–9 C to zero in a
time of 2.0 × 10^–6 s. Calculate the average current in the wire.
current = .............................................................[2]5054/22/M/J/12/q7

Q8. A plastic rod is rubbed with a cloth and becomes negatively charged.
(a) Explain how the rod becomes negatively charged when rubbed with a cloth. [2]
(b) An uncharged metal-coated sphere hangs from an insulating thread. The sphere is brought
near to the rod. The sphere is attracted to the rod, as shown in Fig. 11.1.
 7

(i) Describe and explain what happens to the free electrons in the metal-coated sphere as it
approaches the rod. [2]
(ii) Draw a diagram to show how charge is distributed on the sphere. [1]
(iii) Explain why the uncharged sphere is attracted to the negatively-charged rod. [2]
(c) With the charged rod still close, point X on the metal-coated sphere is earthed.
(i) State what is meant by earthing the sphere. [1]
(ii) Describe and explain what happens to the free electrons in the metal-coated sphere as it is
earthed. [2]
(iii) Draw a diagram to show how the charge is now distributed on the sphere. [1]
(d) Describe one device where electrostatic charging is used. In your answer include a
diagram and explain how and why the charge is produced. [4]
5054/02/M/J/07/q11

Q9.A student rubs a polythene rod with a dry cloth. The polythene rod becomes negatively
charged and the cloth becomes positively charged.
(a) Describe, in terms of the movement of electrons, what happens during the charging
process.
..........................................................................................................................................
..................................................................................................................................... [2]
(b) There is an electric field around the charged rod. Explain what is meant by an electric
field. ..........................................................................................................................................
..................................................................................................................................... [1]
(c) The charged rod is placed near a stream of water from a tap, as shown in Fig. 5.1.
 8

The stream of water bends because the rod is charged.

(i) Explain how the charge on the rod causes positive and negative particles in the water to
move. ..................................................................................................................................
..................................................................................................................................
............................................................................................................................. [2]
(ii) On Fig. 5.1, draw the charge present on the stream of water. [1]
5054/22/M/J/13/q5

Q10.When a balloon is rubbed on hair, the balloon becomes negatively charged. The balloon
is shown in Fig. 5.1.

(a) Explain how rubbing causes the balloon to become negatively charged.
...................................................................................................................................................
...................................................................................................................................................
.............................................................................................................................................. [2]
(b) Explain why the hair is pulled towards the balloon.
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
.............................................................................................................................................. [2]
(c) Explain why it is important that the balloon is made from an electrical insulator.
...................................................................................................................................................
.............................................................................................................................................. [1]
 9

(d) State one example where static electricity is useful.

...................................................................................................................................................
.............................................................................................................................................. [1]
5054/22/M/J/15/q5

Q11.An experiment to show charging by induction uses a metal sphere mounted on an

insulated support. The sphere is initially uncharged and is shown in Fig. 6.1.

(a) A negatively charged rod is brought near the sphere, as shown in Fig. 6.2.

(i) State and explain the movement of electrons in the sphere that occurs as the rod is brought
near. ...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
(ii) On Fig. 6.2, draw the charges on the metal sphere. [3]
(b) The metal sphere is now touched at point A by a wire connected to earth, as shown in Fig.
6.3.
 10

On Fig. 6.3, draw the charges on the metal sphere. [1]

(c) The wire connected to earth is removed. Then the negatively charged rod is also removed,
as shown in Fig. 6.4.

On Fig. 6.4, draw the charges on the metal sphere. [1]

(d) The support is made from an insulator. State one material that may be used to make the
support.......................................................................................................................................[1
]
5054/02 O/N/04/q6

Q12.An electrostatic generator is used to produce sparks, as shown in Fig. 6.1

 11

The belt carries negative charge to the dome, making the dome negatively charged.
(a) Before a spark is produced, the discharge ball becomes positively charged.
(i) Describe and explain the movement of electrons in the discharge ball and in the rod as the
ball becomes charged.
..................................................................................................................................
..................................................................................................................................
..................................................................................................................................
............................................................................................................................ [2]
(ii) On Fig. 6.1, mark with an X where there is the most positive charge on the discharge ball.
[1]
(b) A spark jumps between the dome and the discharge ball when there is enough negative
charge on the dome. A charge of 0.00016 C flows in the spark in a time of 0.012 s.
Calculate the average current in the spark.
State the equation that you use.
current = ............................. [3]
5054/02/O/N/05/q6.

Q13 At an airport, fuel is pumped through a pipe from a tanker to an aeroplane, as shown in
Fig. 6.1.
 12

As it rubs against the pipe, the fuel becomes negatively charged and this charges the
aeroplane.
(a) Explain, in terms of the particles involved, how the fuel becomes negatively charged.
..........................................................................................................................................
..........................................................................................................................................
......................................................................................................................................[2]
(b) Suggest and explain one problem that can arise when an aeroplane becomes charged.
..........................................................................................................................................
..........................................................................................................................................
......................................................................................................................................[2]
(c) To prevent an aeroplane becoming charged, a metal cable connects the aeroplane to the
ground. Explain (i) why the cable is made of metal,
..................................................................................................................................
..............................................................................................................................[1]
(ii) how the cable prevents the aeroplane becoming charged.
..................................................................................................................................
..............................................................................................................................[1]
5054/22/O/N/13/q6

Q14. Two conducting spheres are rubbed and become charged, as shown in Fig. 5.1.
 13

(a) The spheres are uncharged before they are rubbed.

Explain, in terms of the movement of electrons, how they become charged.
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
.................................................................................................................................... [1]
(b) On Fig. 5.1, draw the electric field pattern between the spheres. Show the direction of the
field lines. [2]
(c) A metal wire is used to connect the two spheres together.
In a time of 2.0 × 10–3 s, a charge of 1.8 × 10^–13C passes through the wire.
Calculate the current in the wire.
current = ................................................ [2]
5054/02/M/J/06/q5

ii.Describe simple electric field patterns, including the direction of the field:
(a) around a point charge
(b) around a charged conducting sphere
(c) between two oppositely charged parallel conducting plates (end effects will not be
examined)
 14

Q15

5054/11/M/J/20/q35

Q16

5054/11/M/J/22/q30
 15

Q17

5054/11/O/N/20/q34

Q18

5054/12/M/J/20/
 16

Q19

5054/11/M/J/19/Q31

Applications of electrostatics
Q20
 17

5054/12/M/J/20//q34

Q21
 18

Q22

5054/11/O/N/20/q33

Q23

5054/11/O/N/19/q32

iii conduction in metals in terms of the movement of free electrons

 19

Q24

5054/11/M/J/22/q31

(iv) Electric current:

Q25

3174/12/M/J/21 /q36

Q26

5054/11/M/J/19/Q34
 20

V.Electromotive force and potential difference

Q27

5054/11/M/J/19 /Q32

Q28

5054/12/O/N/20/Q29

Q29.
 21

5054/11/M/J/20/q36
Q30

5054/11/M/J/22/q33
 22

Q31

5054/12/M/J/22 /q33

Q32

5054/12/M/J/19/q34
 23

6.Resistance
6.1VI graphs
Q33

5054/11/M/J/19/Q33

Q34

3174/12/M/J/21 /q37
 24

Q35.

5054/12/M/J/20 /q37

Q36. A filament lamp is labelled 240 V, 0.20 A.

(a) Calculate the resistance of the lamp at normal brightness.

resistance = ................................................ [2]
(b) The lamp is connected to a 240 V supply and switched on at time t = 0.
Fig. 6.1 shows the variation with t of the resistance of the lamp.

Describe how the current in the lamp varies with t.

..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..................................................................................................................................... [2]
(c) A second filament lamp has higher resistance. State two differences between the two
filaments that may cause the change in resistance.
1 The filament in the second lamp is ..............................................................................
..........................................................................................................................................
 25

2 The filament in the second lamp is ..............................................................................

..................................................................................................................................... [2]
5054/02/M/J/08/q6

Resistance
Q37.The circuit of Fig. 7.1 includes an ammeter, a 6.0 Ω resistor, a length of metal resistance
wire and three 1.5 V cells connected in parallel.

(a) State
(i) one advantage of using cells in parallel rather than using a single cell,
...........................................................................................................................................
.......................................................................................................................................[1]
(ii) the potential difference (p.d.) between points P and Q in the circuit of Fig. 7.1.
p.d. = ...........................................................[1]
(b) (i) The ammeter in Fig. 7.1 reads 0.075 A.
Calculate the resistance of the resistance wire. resistance =
...........................................................[3]
(ii) The temperature of the metal resistance wire increases.
State and explain the effect of this temperature increase on the ammeter reading.
...........................................................................................................................................
...........................................................................................................................................
.......................................................................................................................................[2]5054/
22/O/N/14/q7
Q38. (a) Describe an experiment, including an ammeter and a voltmeter, to show how the
resistance of a wire varies with temperature.
Draw a circuit diagram.

..........................................................................................................................................
..........................................................................................................................................
 26

..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
......................................................................................................................................[4]
(b) The filament in a lamp is made from metal wire.
(i) Describe the variation with temperature of the resistance of the filament lamp.
..................................................................................................................................
..................................................................................................................................
..............................................................................................................................[2]

(ii) On Fig. 11.1, sketch a graph of the variation of the current in the filament against the
potential difference (p.d.) across it.

A thermistor is connected in series with a 6.0 V battery and a 2000 Ω resistor.

(i) The temperature of the room increases. State and explain what happens to
1. the reading on the ammeter,
..................................................................................................................................
..............................................................................................................................[2]
 27

2. the reading on the voltmeter.

..................................................................................................................................
..............................................................................................................................[2]
(ii) At a certain temperature, the reading on the voltmeter is 3.8 V.
Calculate the resistance of the thermistor at this temperature.
resistance = ................................[3]5054/22/M/J/10/q11

Q39. An electrical engineer measures the potential difference across a length of metal wire
and the current in the wire. He does this for different values of the current.
(a) (i) Draw a labelled circuit diagram of a circuit that enables the engineer to do this. [3]
(ii) Describe how the circuit is used.
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
.......................................................................................................................................[2]
(iii) State the equation that defines resistance.
.......................................................................................................................................[1]
(b) The engineer performs the experiment and notices that the potential difference across the
wire is directly proportional to the current in it. He calculates the resistance of the wire and
plots a graph of the resistance against the current.
On Fig. 6.1, sketch the shape of this graph.

5054/22/O/N/11 /q6

Q40 (a) Describe an experiment to show the difference between an electrical insulator and an
electrical conductor. Name one example of each.
[4]
(b) Fig. 10.1 is a sketch graph of the current in a component P against the potential difference
(p.d.) across it.
 28

(i) Define resistance. [1]

(ii) State how the resistance of P varies with the p.d. across it. [1]
(iii) Suggest what component P is. [1]
(iv) Explain why the resistance of P varies with the p.d. across it. [2]
(c) Component P is used in the electrical circuit shown in Fig. 10.2.

The current in ammeter 2 is 0.40 A and the current in ammeter 3 is 0.60 A.

(i) Determine the readings of ammeters 1 and 4. [1]
(ii) Calculate the p.d. across the 20 ohm resistor. [2]
(iii) State the p.d. across the power supply. [1]
(iv) Calculate the resistance of P in this circuit. [2]
5054/02/O/N/07/q10
 29

Q41.A motorcycle battery consists of six 2.0 V cells in series. The battery supplies energy to
the headlight. (a) State the total electromotive force (e.m.f.) of the battery.
.................................................................................................................................... [1] (b)
The motorcycle headlight contains two identical filament lamps F and G. Filament lamp F is
always lit but filament lamp G is turned on and off by switch D. Fig. 7.1 is the circuit
diagram.

When switch D is open, the battery supplies a current of 4.6 A.

Complete the table of Fig. 7.2.

(c) Calculate the energy supplied by the battery as an electric charge of 200 C moves through
the circuit.
energy supplied = ................................................ [2]
5054/02/O/N/08/q7
 30

2.Practical electricity
I. Uses of electricity
Q42

5054/11/M/J/22 /q32

Q43

5054/12/M/J/22/q35
 31

ii. State common uses of electricity

Q44.

5054/11/O/N/20/Q39

Q45.

5054/11/M/J/22 /q35
 32

Q46

5054/12/M/J/22/q37

Q47

5054/12/O/N/20/Q30

Q48

5054/12/O/N/20/Q30
 33

Switches,Fuses and circuit breakers:

Q49

5054/12/M/J/22 /q36.
 34

Q50

5054/12/M/J/20/q38

Q51

5054/11/M/J/19/Q35
 35

Q52

5054/12/M/J/19/q36

Q53

5054/11/O/N/19/q36
 36

PRACTICAL ELECTRICITY:
Q54. A microwave oven is rated at 650 W and is connected to a 230 V mains supply.
(a) (i) Calculate the current from the supply when the microwave oven is switched on.
current = ..................................................[2]
(ii) Suggest a rating of the fuse for use with this oven. fuse rating =
..................................................[1]
(b) The insulation of the mains cable has worn away. The live wire touches the outer metal
casing of the microwave oven.
(i) Explain the hazard that results if the outer metal casing is not earthed.
..................................................................................................................................
..................................................................................................................................
..............................................................................................................................[2]
(ii) Explain how connecting the earth wire to the outer casing and using a fuse of a suitable
rating removes this hazard.
..................................................................................................................................
..................................................................................................................................
..................................................................................................................................
..............................................................................................................................[2]
5054/02/O/N/09/q6

Q55..The table gives information about two household appliances.

(a) Write the missing values in the empty spaces in the table. [3]
(b) Why is more power needed for the water heater than for the television?
..........................................................................................................................................
..........................................................................................................................................
.................................................................................................................................... [1]
(c) The water heater is connected to the mains supply. Explain why using a 3 A fuse would
not be suitable.
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
.................................................................................................................................... [2]
5054/02/M/J/05/q6
 37

Q56. Fig. 9.1 shows an electric kettle.

(a) The body of the kettle is plastic but the outside casing of the heating element is metal.
(i) Explain why a fuse is included in the circuit and explain what happens when the fuse
blows. [3]
(ii) Explain why the metal casing of the heating element is connected to earth. [2]
(b) The electrical power input to the kettle is 2000 W and the kettle is used for 6 minutes
(0.1 hour).
Calculate
(i) the electrical energy, in J, supplied to the kettle. State clearly the formula that relates
power, energy and time. [3]
(ii) the electrical energy, in kW h, supplied to the kettle. [2]
(iii) the cost of using the kettle if 1 kW h costs 8 cents. [2]
(c) When the kettle is switched off, the water cools down. Explain, in molecular terms, how
evaporation causes a loss of energy from the water. [3]5054/02/O/N/05/q9

Q57. Fig. 10.1 shows a cable containing three wires coloured brown, blue and yellow/green,
and a mains plug with the cover removed.

(a) Describe how to connect the cable and the three wires correctly and safely to the plug. [4]
(b) The table lamp shown in Fig. 10.2 is made from plastic. It has only two wires in the cable
to connect it to the plug.
 38

The lamp has a power rating of 100 W and is used with a 230 V supply.
(i) Which wire, earth, live or neutral, is not needed in the cable for the lamp? [1]
(ii) Explain why the lamp is safe to use even though it has only two wires in the cable. [2]
(iii) Explain what is meant by a power rating of 100 W. [2]
(iv) Calculate the value of the fuse that should be used in the plug for this lamp. [3]
(v) Calculate the electrical energy supplied to the lamp in 30 minutes. [3]
5054/02/O/N/06/q10
Q58 Fig.11.1 shows a wiring diagram for two different lamps A and B.

(a) State the names of components C and D and explain the purpose, in this circuit,
of each of these components. [4]
(b) When both lamps are working correctly, the current in C is 0.42 A.
Lamp A is marked 240 V, 60 W.
Calculate
(i) the current in lamp A, [2]
(ii) the current in lamp B, [2]
(iii) the resistance of lamp A. [3]
(c) The two lamps in Fig. 11.1 are connected in parallel. When wiring the circuit in a house,
an electrician makes a mistake and connects the two lamps in series to the mains supply. He
switches them on.
(i) Draw a circuit diagram showing the two lamps connected in series to the mains supply.
[1]
(ii) State whether the current in the two lamps is larger than, the same as, or smaller than the
currents you have calculated in (b). Explain your answer. [2]
 39

(d) Another lamp is made using the same material for the filament as lamp A. The filament in
this new lamp has the same length as the filament in lamp A but has half the cross-sectional
area. State the resistance of the new lamp. [1]5054/02/M/J/06/q11

Q59.An electric hairdryer and an electric heater are connected to the mains supply, as shown
in Fig. 7.1.

The cable from the heater to the mains supply has a live, a neutral and an earth wire.
(a) State the purpose of the neutral wire.
...................................................................................................................................................
.............................................................................................................................................. [1]
(b) The live wire in the electric heater touches the outer metal case. Explain how the earth
and the fuse together protect the user from electric shock.
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
.............................................................................................................................................. [2]
(c) The hairdryer does not have an earth wire. Explain why this hairdryer is still safe to use.
...................................................................................................................................................
.............................................................................................................................................. [1]
(d) In some modern homes, circuit breakers are used instead of fuses. Suggest one advantage
of using a circuit breaker rather than a fuse.
...................................................................................................................................................
.............................................................................................................................................. [1]
5054/22/M/J/15/q7
Q60.At night, a bright floodlight is used to illuminate a building. The floodlight is a metal
filament lamp. It is connected in series with a variable resistor and a 230 V mains power
supply. When the floodlight is first switched on, the resistance of the variable resistor is at its
maximum value. In the following few minutes the variable resistor is adjusted so that its
resistance decreases slowly to zero. This causes the brightness of the lamp to increase until it
reaches a maximum. At maximum brightness, the current in the lamp is 12 A.
(a) Calculate the resistance of the lamp at maximum brightness.
resistance = ...............................................[2]
(b) State and explain what happens to the resistance of the lamp as its brightness increases.
..........................................................................................................................................
..........................................................................................................................................
......................................................................................................................................[2]
(c) Suggest how, by using the variable resistor in this way, the filament lamp is protected
from damage.
..........................................................................................................................................
..........................................................................................................................................
......................................................................................................................................[2]
5054/22/O/N/10/q4
 40

Calculating electricity bill:

Q61.An electric saw is rated at 1200 W. When working on a job that lasts for four days, a
workman uses the saw, on average, for 75 minutes each day. The cost of 1 kW h of electrical
energy is 21 cents.
(a) Calculate the cost of using the saw for this job.
cost = ..................................................[3]
(b) The metal case of the electric saw is earthed. Explain how this protects the workman.
..........................................................................................................................................
..........................................................................................................................................
......................................................................................................................................[2]
5054/22/O/N/13/q7

SAFETY IN HOUSEHOLD CIRCUITS

Q62. Fig. 6.1 shows a mains extension lead. The six sockets allow several electrical
appliances to be connected to the mains supply through one cable.

(a) The cable connects the sockets to the mains supply.

The cable contains three wires: live, neutral and earth. State what is meant by
(i) live, ..................................................................................................................................
............................................................................................................................ [1]
(ii) neutral, ..................................................................................................................................
............................................................................................................................ [1]
(iii) earth. ..................................................................................................................................
............................................................................................................................ [1]
(b) Six powerful lamps are plugged into the sockets and switched on, one by one.
(i) State what happens in the cable as the lamps are switched on, one by one.
..................................................................................................................................
............................................................................................................................ [1]
(ii) Describe why it can be dangerous when a fuse of the wrong value is used in the plug.
..................................................................................................................................
..................................................................................................................................
............................................................................................................................ [1]
(c) Explain why your hands should be dry when you put a plug into a socket.
.......................................................................................................................................
 41

.................................................................................................................................... [1]
5054/02/M/J/06/q6
Q63.The cable from the mains plug to a washing machine contains a live wire, a neutral wire
and an earth wire. The earth wire is connected to the metal case of the washing machine.
(a) Explain how connecting the earth wire to the metal case makes the washing machine
safer.
...................................................................................................................................................
...................................................................................................................................................
...............................................................................................................................................[2]
(b) When in use, the average input power to the washing machine is 500 W.
Calculate the number of kW h of energy used by the washing machine in 45 minutes of use.
number of kW h = ................................................[2]
5054/22/M/J/11/q6

Electric circuits
i.Series and parallel circuits
Q64

5054/11/O/N/19/q34
 42

Q65.

5054/11/O/N/20/q36

Q66

5054/11/M/J/22 /q34
 43

Q67.

5054/11/O/N/19/q35

Q68

5054/11/O/N/20/q37
 44

Q69Three cells are connected in series making a battery, as shown in Fig. 8.1.
The e.m.f. of each cell is 1.5 V. A resistance of 15 is connected to the battery.

(a) What is the total e.m.f. of the battery?

.................................................................................................................................... [1]
(b) Calculate the current in the circuit. State the equation that you use.
current = ............................. [3]
(c) A battery can be made from cells connected in parallel, as shown in Fig. 8.2.

State one advantage of connecting the cells in parallel.

..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
.................................................................................................................................... [1]
5054/02/M/J/05/q8.
Q70.The circuit of Fig. 7.1 includes an ammeter, a 6.0 Ω resistor, a length of metal resistance
wire and three 1.5 V cells connected in parallel.
 45

(a) State
(i) one advantage of using cells in parallel rather than using a single cell,
...........................................................................................................................................
.......................................................................................................................................[1]
(ii) the potential difference (p.d.) between points P and Q in the circuit of Fig. 7.1.
p.d. = ...........................................................[1]
(b) (i) The ammeter in Fig. 7.1 reads 0.075 A.
Calculate the resistance of the resistance wire. resistance =
...........................................................[3]
(ii) The temperature of the metal resistance wire increases.
State and explain the effect of this temperature increase on the ammeter reading.
...........................................................................................................................................
...........................................................................................................................................
.......................................................................................................................................[2]5054/
22/O/N/14/q7
Q71.The lamps in a house are connected in parallel to the mains supply. (a) On Fig. 6.1, draw
three lamps and their switches connected to the mains supply.

(b) Each lamp is labelled 240 V, 30 W. Calculate the current in one lamp when it is operating
correctly.
current = .....................................[2]
(c) State the current from the mains supply when the three lamps are switched on.
current = .....................................[1]5054/02/M/J/03/q6

Q72. Fig. 6.1 shows the current-voltage graph for a filament lamp
 46

(a) (i) State the range of voltages where the resistance increases.
............................................................................................................................. [1]
(ii) State why the resistance of the lamp increases as the voltage increases.
..................................................................................................................................
............................................................................................................................. [1]

(b) The filament lamp is connected in the circuit shown in Fig. 6.2.

There are currents in the lamp, the 20 Ω resistor and the ammeter.
(i) State what is meant by an electric current.
..................................................................................................................................
............................................................................................................................. [1]
(ii) Use Fig. 6.1 to determine the current in the filament lamp.
current = .................................................. [1]
(iii) Determine the current in the ammeter.
current = .................................................. [3]
 47

5054/22/M/J/13/q6

SERIES CIRCUITS
Q73.Fig. 8.1 shows an electrical circuit using two resistors.

(a) The switch S is open and the ammeter reading is zero.

State the value of the potential difference across the 6 ohm resistor.
potential difference = ............................. [1]
(b) Switch S is now closed.
(i) State the value of the total resistance of the circuit.
resistance = .............................................[1]
(ii) Calculate the current in the ammeter.
State clearly the formula that you use. current = ..................................................[2]
(iii) Calculate the potential difference across the 6 ohm resistor.
p.d. = .......................................................[2]5054/02/O/N/06/q8

Q74.Fig. 11.1 shows a 9.0 V battery connected in series with a 16.0 Ω resistor and a small
metal conductor X at room temperature.
 48

A voltmeter measures the potential difference (p.d.) across the 16.0 Ω resistor. At room
temperature the resistance of X is 4.0 Ω.
(a) (i) Calculate the current supplied by the battery. [2]
(ii) Calculate the p.d. across the 16.0 Ω resistor. [1]
(b) X is heated slowly to a very high temperature.
(i) Sketch a graph to show how the resistance of a metal conductor depends on its
temperature. [2]
(ii) State and explain how the voltmeter reading changes as the temperature of X rises. [2]
(iii) Suggest a suitable range for the voltmeter. [2]
5054/02/O/N/09/q11

Q75.Fig. 7.3 shows a 4700 Ω resistor connected in series with a variable resistor. The
variable resistor can have any value between 0 and 4700 Ω.

As the resistance of the variable resistor is altered, determine

(i) the largest reading on the voltmeter, ........................................................................
(ii) the smallest reading on the voltmeter. ...................................................................... [2]
5054/02/M/J/03/q7

Q76.Fig. 6.1 shows a circuit in which a voltmeter is placed across a resistor.

 49

The potential difference across the 12 Ω resistor is 4.0 V.

The voltmeter has three different ranges: 0 to 3.0 V, 0 to 6.0 V and 0 to 30 V.
The best range for use in this circuit is 0 to 6.0 V.
(a) Explain why
(i) using the voltmeter on the range 0 to 3.0 V is unsuitable,
...................................................................................................................................
...................................................................................................................................
(ii) using the voltmeter on the range 0 to 30 V is unsuitable.
...................................................................................................................................
................................................................................................................................... [2]
(b) (i) Calculate the current in the 12 Ω resistor. State the formula that you use.
current = …………………
(ii) Calculate the p.d. between A and B in Fig. 6.1.
5054/02 M/J/04/q6
Q77.Fig. 7.1 shows an electrical circuit.

(a) On Fig. 7.1, draw an arrow at A to show the direction of flow of the electrons in the wire.
[1]
 50

(b) What is the name of component X?

.................................................................................................................................... [1]
(c) State and explain how the potential difference across X varies as the light shining on it
becomes brighter.
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
..........................................................................................................................................
.................................................................................................................................... [2]
5054/02/M/J/05/q7
MIXED CIRCUITS
Q78.Fig. 7.1 shows an electrical circuit containing a 12 V power supply and a number of
resistors.

(a) Calculate the combined resistance of

(i) the 2 Ω and 4 Ω resistors in series,
resistance = ................................................ [1]
(ii) the 3 Ω and 6 Ω resistors in parallel.
resistance = ................................................ [2]
(b) Calculate the reading of the ammeter in Fig. 7.1.
ammeter reading = ................................................ [2]
(c) Determine the potential difference across the 4 Ω resistor.
p.d. = ................................................ [2]5054/02/M/J/07/q7

Q79A student investigates how the resistance of a wire depends upon its length. The student
uses an ammeter, a voltmeter, a battery, a fixed resistor and the wire under test, all connected
in an electrical circuit.
(a) (i) In the space below, draw a circuit diagram of the apparatus.
Label the wire under test with the letter W. [3]
 51

(ii) Describe how the student obtains one complete set of results.
...........................................................................................................................................
...........................................................................................................................................
.......................................................................................................................................[2]
(iii) During the experiment, the student keeps the temperature of the wire constant. 1.
Suggest why it is sensible to keep the temperature of the wire
constant.........................................................................................................................................
.. .......................................................................................................................................[1] 2.
Suggest how the student keeps the temperature of the wire constant.
...........................................................................................................................................
.......................................................................................................................................[1]
(b) Fig. 8.1 shows part of a circuit containing three resistors X, Y and Z.

The resistance of X and the resistance of Y are each 10 Ω. The current through X is 0.30 A.
The current through Y is 0.20 A.
(i) Calculate the potential difference (p.d.) across Y. p.d. =
...................................................................[2]
(ii) Calculate the current I in resistor Z.
I = .......................................................................[1]
(iii) Explain in words, rather than by calculation, how Fig. 8.1 shows that the resistance of Z
is larger than the resistance of Y.
Use ideas about p.d. and current in your answer.
...........................................................................................................................................
...........................................................................................................................................
.......................................................................................................................................[2]
(iv) Calculate the total resistance of the resistors X, Y and Z in this circuit.
resistance = ........................................................[3]
5054/22/M/J/12/q8

Q80. A student sets up the circuit shown in Fig. 11.1.

 52

R is a fixed resistor in the circuit. The filament lamp is marked 12 V, 0.25 A. The circuit is
used to produce a current/voltage graph for the filament lamp. The ammeter and voltmeter
needed are not shown. To obtain different readings, the student changes the position of the
movable contact.
(a) On Fig. 11.1, draw the symbols for an ammeter and a voltmeter in the correct positions.
[3]
(b) Explain why it is sensible to include the resistor R in this circuit.
...................................................................................................................................................
...................................................................................................................................................
.............................................................................................................................................. [2]
(c) (i) On Fig. 11.2, sketch a current/voltage graph for the lamp.

(ii) State and explain how a current/voltage graph for a fixed resistor is different from the
graph for a filament lamp.
...........................................................................................................................................
 53

...........................................................................................................................................
...................................................................................................................................... [2]
(d) Fig. 11.3 shows the position of the movable contact when the voltage across the lamp is
12 V and the current in the lamp is 0.25 A.

Determine (i) the current in the 50 Ω resistor,

current = .......................................................... [2]
(ii) the current in R,
current = .......................................................... [1]
(iii) the potential difference (p.d.) across R,
p.d. = .......................................................... [1] (iv) the resistance of R.
resistance = .......................................................... [1]
5054/22/M/J/14/q11
Q81. Fig. 11.1 shows how the currents in a lamp L and in a wire W vary with the potential
difference (p.d.) applied.

\
(a) (i) Draw a diagram of the circuit that you would use to take the readings of current and
p.d. for the lamp. State the range you would choose for the voltmeter. [5]
(ii) Describe how the resistance of the lamp L varies as the p.d. increases. [1]
(b) (i) Fig. 11.2 shows the lamp L and the wire W connected in series.
The current in the circuit is 0.8 A.
 54

Determine, using the graph or by calculation,

1. thep.d. across L,
2. thep.d. across W,
3. thep.d. of the supply,
4. the resistance of the lamp L in Fig. 11.2

(ii) Fig. 11.3 shows the lamp and wire connected in parallel. A p.d. of 12 V is connected
across them.

Determine, using the graph or by calculation,

1. the current Iwin the wire W,
2. the current in the lamp L,
3. the total current I in the circuit,
4. the resistance of the wire W.
5054/02/O/N/05/q11
Q82 (a) A lamp is marked 24 V, 100 W. Describe an experiment to check that the electrical
power supplied to the lamp is 100 W when the potential difference (p.d.) across it is 24 V. In
your account you should • include a circuit diagram, • state the readings that are taken, • show
how the result is calculated from the readings. [4] (b) Two lamps are connected in parallel to
a 240 V mains supply, as shown in Fig. 9.1.
 55

Lamp A has a resistance of 190 Ω and lamp B has a resistance of 380 Ω.

(i) Calculate the current at points P, Q and R. [3]
(ii) Calculate the total resistance of the circuit. [2]
(c) Fig. 9.2 shows the same lamps connected in series to the mains supply.

(i) Calculate the current at point S. [2]

(ii) Calculate the p.d. across lamp A. [1]
(d) In a house, all lamps are connected in parallel to the mains supply, not in series. State and
explain two reasons for this. In your explanation you may refer to the results of your
calculations in (b) and (c). [3]5054/02/M/J/09/q9
 56

Q83.Fig. 5.1 shows part of a low-voltage lighting circuit.

The power supply voltage is 12 V.

(a) On Fig. 5.1, complete the circuit, adding components as necessary,
so that:
• the total current in the circuit can be measured,
• lamp A is on all the time,
• lamps B and C are in series with each other and are switched on or off together. [3]
(b) All the lamps are on. The potential difference (p.d.) across lamp B is 8.0 V and the current
in lamp B is 50 mA.
(i) Calculate the resistance of lamp B. resistance = ........................................................ [2]
(ii) State the current in lamp C. current = ............................................................. [1]
5054/22/M/J/11/q5
 57

Calculate current, voltage and resistance in parts of a circuit or in the whole circuit

Q84

5054/12/M/J/22 /q34
 58

Q85

5054/11/O/N/20/q35

Q86

5054/12/O/N/20/Q38
 59

Q87

3174/12/M/J/21 /q35

VARIABLE RESISTORS,LDR AND THERMISTOR

Q88

5054/11/O/N/20/Q38
 60

Q89

5054/12/M/J/19/Q33

Furth practice of Theory/Structured questions

Q90
 61

5054/21/M/J/22/q6

Q91
62
 63

5054/22/M/J/22/q5
 64

Q92
65
 66

5054/21/M/J/21/q9

Q93.
67
68
 69

5054/22/M/J/21/q5

Q94.
 70

5054/22/M/J/21/q8
 71

Q95. EMF and TPD

5054/21/O/N/21 /q6
 72

Q96.

5054/22/O/N/21/q5
 73

Q97
74
 75

5054/21/M/J/20/q8

Q98
 76

5054/22/M/J/20/q6
 77

Q99.
 78

5054/21/O/N/20/q10
 79

Q100.

5054/22/O/N/20/q5
 80

Q101.
 81

5054/21/M/J/19/Q5

Q102
 82

5054/21/M/J/19/Q6

Q103.
 83

5054/22/M/J/19/q6
 84

Q104

5054/21/O/N/19 /q6