Y10 Electricity Practice Questions Name:.........................

Question1

9 The graphs in Fig. 9.1 show the relation between the current I and the potential difference V for a
resistor and a lamp.

5
I/A
4 lamp

2 resistor

0
0 1 2 3 4 5 6 7 8 9
V/V

Fig. 9.1

(a) (i) Describe how, if at all, the resistance varies as the current increases in

1. the resistor, ...................................................................................................................

2. the lamp. ...................................................................................................................[2]

(ii) State the value of the potential difference when the resistor and the lamp have the same
resistance.

potential difference = ...........................................................[1]

(b) The two components are connected in parallel to a supply of e.m.f. 4.0 V. Calculate the total
resistance of the circuit.

total resistance = ...........................................................[4]

[Total: 7]

© UCLES 2011 0625/31/O/N/11

Question 2 2

9 Fig. 9.1 shows the circuit that operates the two headlights and the two sidelights of a car. For
Examiner’s
A Use
1

2
3

12 V 4.0 1 4.01 121 121

Fig. 9.1

Two of the lamps have resistances of 4.0 Ω when lit. The other two lamps have resistances of
12 Ω when lit. Switch A can be connected to positions 1, 2 or 3.

(a) State what happens when switch A is connected to

(i) position 1, .................................................................................................................

(ii) position 2, .................................................................................................................

(iii) position 3. .................................................................................................................

[1]

(b) (i) State the potential difference across each lamp when lit.

potential difference = .................................................. [1]

(ii) Calculate the current in each 12 Ω lamp when lit.

current = .................................................. [2]

(c) Show, with reasons for your answer, which type of lamp, 4.0 Ω or 12 Ω, has the higher
power.

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

...................................................................................................................................... [3]

[Total: 7]

© UCLES 2013 0625/31/M/J/13 [Turn over

Question 3 3

9 (a) State the relationship between For

Examiner’s
(i) the resistance R and the length L of a wire of constant cross-sectional area, Use

..................................................................................................................................

(ii) the resistance R and the cross-sectional area A of a wire of constant length.

..................................................................................................................................
[1]

(b) A 60 W filament lamp X is connected to a 230 V supply, as shown in Fig. 9.1.

230 V

Fig. 9.1

Calculate the current in the filament.

current = .................................................. [2]

© UCLES 2013 0625/31/O/N/13

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(c) Lamp Y has a filament made of the same metal as the filament of lamp X in (b). For
Examiner’s
This filament has half the length and one-third of the cross-sectional area of the filament Use

of X.

Lamp Y is also connected to a 230 V supply.

Calculate the ratio current in filament of Y . Show your working.

current in filament of X

ratio = .................................................. [4]

[Total: 7]

© UCLES 2013 0625/31/O/N/13 [Turn over

Question 4 5

9 In the circuit shown in Fig. 9.1, resistors can be connected between terminals P and Q. The e.m.f.
of the battery is 6.0 V.

6.0 V

P Q

Fig. 9.1

(a) Calculate the current shown by the ammeter when a 12.0 Ω resistor and a 4.0 Ω resistor are

(i) connected in series between P and Q,

current = ............................................... [2]

(ii) connected in parallel between P and Q.

current = ............................................... [3]

(b) State the relationship between

(i) the resistance R and the length l of a wire of constant cross-sectional area,

...........................................................................................................................................

(ii) the resistance R and the cross-sectional area A of a wire of constant length.

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

(c) The 12.0 Ω and 4.0 Ω resistors in (a) are wires of the same length and are made of the same
alloy.

cross-sectional area of 12.0 Ω resistor

Calculate the ratio:
cross-sectional area of 4.0 Ω resistor

ratio = ............................................... [1]

[Total: 8]
© UCLES 2014 0625/31/M/J/14
Question 5
6

9 In Fig. 9.1, a 12 V battery supplies a current I to a circuit. The circuit contains a thermistor and a
1000 Ω resistor in parallel, with a 500 Ω resistor in series.

12 V

500 1

1000 1

Fig. 9.1

(a) At a certain temperature, the thermistor has a resistance of 1000 Ω.

Calculate

(i) the combined resistance of the thermistor and the 1000 Ω resistor,

resistance = ................................................ [2]

(ii) the current I,

current = ................................................ [1]

(iii) the potential difference across the 500 Ω resistor.

potential difference = ................................................ [2]

© UCLES 2015 0625/31/M/J/15

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(b) The temperature of the thermistor is increased so that its resistance decreases.

State the effect of this change in resistance on the current through the 500 Ω resistor. Explain
your answer.

...................................................................................................................................................

...................................................................................................................................................

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

[Total: 7]

© UCLES 2015 0625/31/M/J/15 [Turn over

 8
Question 6

9 Fig. 9.1 shows a 12 V battery connected in a circuit containing resistors A, B, C and D. Each resistor
has a resistance of 6.0 Ω.

12 V

A B

Fig. 9.1

(a) Calculate the combined resistance of

(i) resistors A and B,

resistance = ................................................................. [1]

(ii) resistors A, B and C,

resistance = ................................................................. [2]

(iii) resistors A, B, C and D.

resistance = ................................................................. [1]

© UCLES 2016 06_0625_41_2016_1.10

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(b) Calculate

(i) the current in the battery,

current = ................................................................. [1]

(ii) the energy transferred from the battery to the circuit in 50 s.

energy transferred = ................................................................. [2]

[Total: 7]

© UCLES 2016 06_0625_41_2016_1.10 [Turn over

Question 7
10

7 Fig. 7.1 shows a circuit diagram that includes component X.

A
X

20 Ω

30 Ω

Fig. 7.1

(a) State the name of component X.

............................................................................................................................................. [1]

(b) The electromotive force (e.m.f.) of the battery is E. The switch is closed.

The potential difference (p.d.) across the 30 Ω resistor is V30.

The p.d. across the 20 Ω resistor is V20.
The p.d. across component X is VX.

State an equation that relates VX to:

(i) V30

..................................................................................................................................... [1]

(ii) E and V20.

..................................................................................................................................... [1]

© UCLES 2019 0625/41/M/J/19

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(c) The e.m.f. of the battery is 6.0 V and the resistance of component X is 15 Ω.

Calculate:

(i) the total resistance of the circuit

resistance = ......................................................... [3]

(ii) the ammeter reading.

reading = ......................................................... [2]

(d) The temperature of component X increases.

State and explain what happens to the ammeter reading.

...................................................................................................................................................

...................................................................................................................................................

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

[Total: 10]

© UCLES 2019 0625/41/M/J/19