SASS Prelim 2024

Index Class Number Candidate Name ___________________________________ ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ST ANDREW’S SCHOOL ELECTRONICS PAPER 1 6063/01 THURSDAY 15 AUGUST 2024 2 hours INSTRUCTIONS TO CANDIDATES Do not open this question paper until you are told to do so. READ THESE INSTRUCTIONS FIRST Write in dark blue or black pen. Do not use staples, paper clips, highlighters, glue or correction fluid. Answer all questions from Section A and Section B. Write your answers to Sections A and B in the spaces provided on the question paper. You may use a soft pencil for any diagrams, graphs or rough working. Candidates are reminded that all quantitative answers should include appropriate units. Candidates are advised to show all their working in a clear and orderly manner, as more marks are awarded for sound use of physics than for correct answers. At the end of the examination, fasten any separate answer paper securely to the Question paper. This question paper consists of 23 printed pages. [Turn over ELECTRONICS7015YHG © SAS 2024 ST ANDREW’S SECONDARY SCHOOL PRELIMINARY EXAMINATION 2024 SECONDARY 4 EXPRESS 100 FOR EXAMINER'S USE

DATASHEET Resistor Colour Codes 1st Colour Band 1st Digit 2nd Colour Band 2nd Digit 3rd Colour Band Multiplier 4th Colour Band Tolerance Black 0 Brown 1 Red 2 Orange 3 Yellow 4 Green 5 Blue 6 Violet 7 Grey 8 White 9 Black 0 Brown 1 Red 2 Orange 3 Yellow 4 Green 5 Blue 6 Violet 7 Grey 8 White 9 Black 0 Brown 1 Red 2 Orange 3 Yellow 4 Green 5 Blue 6 Violet 7 Silver 0.01 Gold 0.1 Gold ± 5% Silver ± 2% Preferred values for resistors (E24 SERIES) 1.01.11.21.31.51.61.82.02.22.42.7 3.0 3.3 3.63.94.34.75.15.66.26.87.5 8.2 9.1 and multiples of ten. FORMULAE Astable and monostable generators using 555 timers Monostable mode Period T = 1.1RC Astable mode Period T = (R1+2R2)C 1.44 ton = 0.7(R1 + R2) C toff = 0.7 R2 C Bipolar junction transistor (BJT) Current gain, β = Collector current Base current Voltage gain (for voltage-divider biased CE amplifier, emitter resistor unbypassed) ≅ −RC RE

Prelim Examination 2024/Sec 4E/Electronics P1 3 [Turn over Table on Boolean Algebra Laws of Complementation 0=1 1=0  ̿ A =A AND Laws A.0=0 A∙1=A A∙A=A A∙A=0 Single variable theorems OR Laws A+0=A A+1=1 A+A=A A+A=1 Commutative Laws A+B=B+A A∙B=B∙A Associative Laws A+(B+C)=(A+B)+C=A+B+C A∙(B∙C)=(A∙B)∙C=A∙B∙C Distributive Laws A∙(B+C)=A∙B+A∙C ;  (A+B)∙(C+D)=A∙C+B∙C+A∙D+B∙D Absorptive Laws A+A∙B=A A∙(A+B)=A A+̅ A ∙B=A+B

Prelim Examination 2024/4E/Electronics P1 4 A∙( ̅ A +B)=A∙B Multivariable theorems DeMorgan’s Theorems (A+B)=A∙B (A∙B)=A+B SECTION A [ 40 marks ] Answer all the questions in the spaces provided. 1 Fill in the missing component name or draw the missing component symbol in the table below. [2] Component name Symbol Polarised capacitor 2 All electronic systems can be broken down into three main system blocks – Input, Process and Output A list of component units has been provided for you below. Temperature sensing unit Motor unit SR latch unit

Prelim Examination 2024/Sec 4E/Electronics P1 5 [Turn over Moisture sensing unit OR gate Bulb unit Write them down under the correct sub-system. The first unit has been placed for you. [5] Input sub-system Process sub-system Output Subsystem Moisture sensing unit 3 A network of resistors is used in the following circuit. (i) Calculate the resultant resistance of the whole circuit shown. ………………………………………………………………………………[2] (ii) Determine V1, the potential difference across the 1 Ωk resistor. 9 V 0 V I1 I2 1 KΩ 3 KΩ6 KΩ V1

Prelim Examination 2024/4E/Electronics P1 6 ….……………………………………………………………………………[2] (iIi)Determine the value of I1 and I2. I1 =...………………………………………………………………………… I2 =...………………………………………………………………………… [2] (iv)Determine the energy generated by the 6 kΩ resistor in 6 min. ….……………………………………………………………………………[2] (v) The resistance of the wires has been ignored. Calculate the resistance of the wires given that they are made copper, cross-sectional area = 2 x 10-7 m2, and the total length of the wires used in the circuit is 1.2 m. Resistivity of copper = 1.7 x 10-8 Ωm. ….……………………………………………………………………………[2] 4 The figure below shows a circuit. The directions of the currents are indicated. (a) Using KVL, form equations for the loops ABEFA and BCDEB. V1 V2 V3 V4E1 E2 I1 I2 I3 A B C DEF

Prelim Examination 2024/Sec 4E/Electronics P1 7 [Turn over ABEFA =...…………………………………………………………………….. BCDEB =...……………………………………………………………………. [2] (b) Given E1 = 12 V, V2 = 2 V, V3 = 4 V, E2 = 5 V, use the equations obtained in (a) to determine V1 and V4. V1 =...………………………………………………………………………… V4 =...………………………………………………………………………… [2] (c) Given I1 = 15 mA and I3 = 20 mA, determine I2. I2 =...…………………………………………………………………………[1] 5 A sinusoidal waveform has a peak-to-peak value Vpp = 8 V and frequency of 50 Hz. (a) Determine the period of the wave. ...…………………………………………………………………………….[1] (b) Draw 3 complete waveforms in the graph below. Label the appropriate voltage and time accurately. [2] V / V

Prelim Examination 2024/4E/Electronics P1 8 (c) Another waveform is shown below. (i) Name the type of waveform shown. ...…………………………………………………………….……….[1] (ii) The signal is then adjusted so that the duty cycle of the waveform is now 70%. Draw the new waveform in the diagram below. [2] 6 An RC circuit is shown below. t / ms 10 -10 Red green blue gold 47 V / V t / ms5 10 15 20 25 V / V t / ms5 10 15 20 25

Prelim Examination 2024/Sec 4E/Electronics P1 9 [Turn over (a) Determine the resistance of the resistor. ...…………………………………………………………………………….[1] (b) Determine the capacitance of the non-polarised capacitor. ...…………………………………………………………………………….[1] (c) Calculate the time constant of the circuit. ...…………………………………………………………………………….[1] (d) Determine the time taken for the capacitor to be charged to 9 V once the circuit is closed. ...…………………………………………………………………………….[1] 7 A circuit involving a NOT, NOR and AND gate is shown below. Use a pencil and ruler to draw connections from the three IC chips below to connect the circuit above. Label your inputs and outputs and use the gates that are circled. You may assume that the VCC and GND connections are already made. [3] 9 V W E R J

Prelim Examination 2024/4E/Electronics P1 10 8 Convert the following Decimal, Binary and BCD to fill in the blanks in the table below [5] Decimal Binary BCD 20 0001 0100 11001101 0110 0110 SECTION B [60 marks] Answer all the questions in the spaces provided. 9 (a) A student has designed a s