MS2 / WELSH JOINT EDUCATION COMMITTEE
£2.00 / CYD-BWYLLGOR ADDYSG CYMRU

General Certificate of Secondary EducationTystysgrif Gyffredinol Addysg Uwchradd

MARKING SCHEMES

SUMMER 2006

ELECTRONICS (MODULAR)

INTRODUCTION

The marking schemes which follow were the ones used by the WJEC for the SUMMER 2006 examination in the GCSE ELECTRONICS papers . They were finalised after detailed discussion at examiners' conferences by all the examiners involved in the assessments. The conferences were held shortly after the papers were taken so that reference could be made to the full range of candidates' responses, with photocopied scripts forming the basis of discussion. The aim of the conference was to ensure that the marking schemes were interpreted and applied in the same way by all examiners.

It is hoped that this information will be of assistance to centres but it is recognised at the same time that, without the benefit of participation in the examiners' conference, teachers may have different views on certain matters of detail or interpretation.

The WJEC regrets that it cannot enter into any discussion or correspondence about these marking schemes.

GCSE Electronics: Module E1 Foundation Tier May 2006 Mark Scheme

Question / Answers/Explanatory Notes / Marks Available
1 / a
b
c / bulb
sensor
latch / 1
1
1
[3]
2. / a.
b.
c / LDR
variable resistor
LDR [not light sensor] / 1
1
1
[3]
3. / magnetic (1)
tilt (1) / 2
[2]
4. / 1 mark per correct sequence (2  1) / 2
[2]
5. / a.
b.
c. / light-sensing unit
OR
transistor / transistor driver / 1
1
1
[3]
6. / a.
b.
c. / 6
10
4 / 1
1
1
[3]
7. / a.
b.
c. / (i)
(ii) / 20 m[W]
10 m[A] (1)
3 [V] (1)
correct use of 3 V and 10 mA (1); 300 [](1)
[use of 5 V or 2 V with 10 mA  1 max]
330 [] or 270 [] e.c.f. / 1
2
2
1
[6]
Question / Answers/Explanatory Notes / Marks Available
8. / a.
b.
c. / (i)
(ii) / Band 1 – Brown (1)
Band 2 – Black (1)
Band 3 – Orange (1)
Correct significant figures (33) (1)
Correct multiplier (10) (1) [i.e. 330 ]
15 k[]
[V] (1) / 3
2
1
2
[7]
9. / (i)
(ii) / / 5
[5]
10. / a.
b. / (i)
(ii) / pin 1 labelled (1)
pin 7 labelled (1)

Thermistor diagram:
/ 2
1
2
[5]

TOTAL FOUNDATION TIER

/ 40
GCSE Electronics: Module E1 Higher Tier May 2006 Mark Scheme
Question / Answers/Explanatory Notes / Marks Available
1. / a.
b.
c / LDR
variable resistor
LDR [not light sensor] / 1
1
1
[3]
2. / a.
b.
c.
d. / (i)
(ii) / (1)
10 m[A]
3 [V]
correct use of 3 V and 10 mA (1); 300 [](1) e.c.f.
[use of 5 V or 2 V with 10 mA  1 max]
330 [] only e.c.f. [i.e. next R up] / 2
2
2
1
[7]
3. / a.
b.
c. / (i)
(ii) / Band 1 – Brown (1)
Band 2 – Black (1)
Band 3 – Orange (1)
Correct significant figures (33) (1)
Correct multiplier (10) (1) [i.e. 330 ]
363 [] (1)
297 [] (1)
[5% used correctly  1max]
[V] (1) / 3
2
2
2
[9]
Question / Answers/Explanatory Notes / Marks Available
4. / a.
b. / temperature sensor (1)
AND (1)
P: magnetic switch(1)
Q: latch [not transducer driver] (1)
R: time delay (1)
S: AND (1)
T: Transducer driver (1) / 2
2
3
[7]
5. / a.
b.
c. / (i)
(ii)
(i)
(ii) / VA / VB / VC / Buzzer
on/off
05 V / 05 (1) / 0 (1) / OFF
ON
35 V / 0607(1) / 5 (1)

06  08 (1) = 20 e.c.f. [27  b(i)] (1)
/ 5
1
2
2
[10]
6. / a.
b. / 0 (1)
6 (1)
thermistor and resistor symbols (1)
thermistor at top [accept l.d.r or l.e.d.] (1) / 2
2
[4]

TOTAL HIGHER TIER

/ 40
GCSE Electronics: Module E2 Foundation Tier June 2006 Mark Scheme
Question / Answers/Explanatory Notes / Marks Available
1 / a
b
c / Micro switch
Solenoid
Time delay / 1
1
1
[3]
2. / a.
b.
c.
d. / Pin 1 label
4
2
NOR / 1
1
1
1
[4]
3. / a.
b.
c. / (i)
(ii)
(iii) / Light Sensing Unit
Pulse Generator
Pulse Generator
Transistor
A to D conversion / immune to chatter/ conditioning / 1
1
1
1
1
[5]
4 / 1011111
0011111
2 / 1
1
1
[3]
5. / On
On
Off / 1
1
1
[3]
6. / a.
b.
c.
d. / Monostable
4 minute
4 volts
Suitable application e.g. egg timer /security light clock – allow burglar alarm. / 1
1
1
1
[4]
Question / Answers/Explanatory Notes / Marks Available
7 / a.
b. / (i)
(ii) /
Q
1
0
Q
0
0
0
1
C / Q
1 / 0
1 / 1
0 / 0
0 / 0
(1) (1)[e.c.f. CQ] / 1
1
2
[4]
8. / a.
b. / (i)
(ii)
(i)
(ii) / Connection from Pulse Generator to Clock (1)
Connection from to D (1)
[allow 1 extra connection – b.o.d.]

200 Hz

3rd (1)
2 [e.c.f. i.e. 1 less than (i)] (1) / 2
1
2
[5]
9. / a.
b
c. / (i)
(ii)
(iii)
(i)
(ii)
(iii) / OR (1)
NAND(1)
NOT A (accept inverter or NOT gate) (1)
Each gate + connections 3  (1)
Re-programmable [accept: more compact or equiv.](1)
6 (1)
8 (1) / 3
3
3
[9]
TOTAL FOUNDATION TIER
/ 40
GCSE Electronics: Module E2 Higher Tier Jun 2006 Mark Scheme
Question / Answers/Explanatory Notes / Marks Available
1. / 1011111
0011111
2 / 3
[3]
2. / a.
b. / On (1)
On (1)
Push to make switch across thyristor or
make switch in the 9V rail / 2
1
[3]
3 / a.
b.
c.
d. / Monostable
4 minute
4 volts
Suitable application eg egg timer /security light
[Accept burglar alarm only if qualified for limited duration of alarm.] / 1
1
1
1
[4]
4. / a.
b.
c. / (i)
(ii)
(iii)
(i)
(ii)
(iii) / Q: OR (1)
R: NAND (1)
S= NOT A [or “inverse of A”, not just “inverter”] (1)
Each gate + connections 3  (1)
Re-programmable / compactness. (1)
6(1)
8(1) / 3
3
3
[9]
5. / a.
b / (i)
(ii) / Connection from to D 2 x [1]
Connection from to on first D-type to clock on second
5
4 / 2
1
1
1
[5]
6. / a.
b.
c. / C / D / Q
1 / 0 / 0
1 / 1 / 1
0 / 1 / 0
0 / 1 / 0
(1) (1) (1)
NOT equivalent drawn (1)
AND equivalent drawn (1)
OR equivalent drawn (1)
Correct pair of NANDs crossed out / 3
3
1
[7]
7. / a.
b.
c. / (i)
(ii)
(i)
(ii) / Suitable sketch showing at least two pulses of ~ equal amplitude.
Substitution (1)
Correct multipliers / answer (1∙25) (1) Hz(1)
to improve [reduce] the rise time of the signal from light sensor [accept reference to hunting/ signal conditioning]
Appropriate interface (transistor / MOSFET / relay, but not transducer driver)
Correct symbol for interface (1)
Input connection (1)
Output connections (1) / 1
3
1
1
3
[9]
TOTAL HIGHER TIER
/ 40

Electronics Terminal Paper – Foundation 2006 – Mark Scheme

Question / Answers/Explanatory Notes / Marks Available
1. / a.b.c. / Solenoid (1)
light sensor (1)
time delay (1) / 3
[3]
2 / a.
b. / LED (1)
LDR (1) / 2
[2]
3. / a.
b.
c. / Light-sensing unit (1)
AND (1)
Transducer driver (1) / 3
[3]
4 / a.
b. / (i)
(ii)
(i)
(ii) / C (1)
A (1)
Band 1 – brown (1)
Band 2 – black (1)
Band 3 – orange (1)
[V] (1) / 2
3
2
[7]
5. / / 4
[4]
6. / a.
b.
c. / Time delay
B
suitable use, e.g. egg timer / 1
1
1
[3]
Question / Answers/Explanatory Notes / Marks Available
7. / a.
b.
c. / (i)
(ii) / NOT / invert (1)(1)

AND (1) (1)
NAND(1)
Correct symbol (1)
/ 4
2
3
[9]
8. / a.
b. / (i)
(ii) / 101
A1 to AND i/p (1); A2 to AND i/p(1); o/p to reset (1)
3 [s] / 1
3
1
[5]
9. / a.
b. / 1 per correct label (41)
/ 4
2
[6]
10. / a.
b.
c. / (i)
(ii)
(iii)
(iv) / 1 per box [alt 1 per correct sequence] (4  1)
aerial (1)
demodulator (1)
headphones (1)
tuned circuit (1)
correct amplitude shown (1)
correct number of cycles shown (1) / 4
4
2
[10]
11. / a.
b. / (i)
(ii) / 1 per correct label (3  1)
A
A / 3
1
1
[5]
Question / Answers/Explanatory Notes / Marks Available
12. / a.
b. / 08 (1); 12 (1)
0100 (1); 0110 (1) / 2
2
[4]
13. / a.
b.
c.
d. / thermistor
e.g. comfort / efficiency
e.g. to prevent hunting
/ 1
1
1
6
[9]

Electronics Terminal Paper Higher 2006Mark Scheme

Question / Answers/Explanatory Notes / Marks Available
1. / a.
b.
c. / (i)
(ii)
(i)
(ii) / C (1)
A (1)
Band 1 – brown (1)
Band 2 – black (1)
Band 3 – orange (1)
10500  (1) & 9500  (1)
[V] (1) / 2
3
2
2
[9]
2. / a.
b. / (i)
(ii) /



25  07 (e.c.f.) = 18 (ans)
= 45 k[](1) / 3
2
1
2
[8]
3. / a.
b. /
1 mark per correct gate (3  1) / 3
3
[6]
4. / a.
b.
c. / (i)
(ii) / 101
A1 to AND i/p & A2 to AND i/p(1); o/p to reset (1)
3 [s]
8 / 1
2
1
1
[5]
Question / Answers/Explanatory Notes / Marks Available
5. / a.
b.
c. / on
stays on
off / 1
1
1
[3]
6. / a.
b.
c. / 5  50 m[V] (1) = 250 m[V]
3  (1) 05 m[s] = 15 m[s] (1)
/ 1
2
2
[5]
7. / a.
b.
c.
d. / (i)
(ii) / A: aerial (1). B: tuned circuit (1)
picks up radio waves
selects station
diode in correct place [either orientation] (1)
filtercapacitor in correct place (1)
o/p e.g. headphones / speaker in correct place (1)
correct amplitude [approx.] (1)
correct no. of cycles [approx] (1) / 2
1
1
3
2
[9]
8. / a.
b.
c. / (i)
(ii)
(i)
(ii)
(iii) / 1 per correct label (3  1)

10 m[V]  16 (e.c.f.) (1) = 160 m[V](1)
correct plots (± ½ square) (1); smooth line (1)
70% of 70 [accept 50] (1); clearly indicated at both ends (1)
~15 k[Hz] / 3
2
2
2
2
1
[12]
9. / a.
b. / 08 (1); 12 (1)
0100 (1); 0110 (1)
Any sensible answer, e.g. reduce [effect of] noise / 2
2
1
[5]
Question / Answers/Explanatory Notes / Marks Available
10. / a.
b.
c. / e.g. comfort / efficiency
e.g. to prevent hunting
/ 1
1
6
[8]

1

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