# Electrical Technology Grade 12 NSC June 2022 QP (Eng) > Grade 12 Electrical Technology question paper from the NSC June Exam 2022 (English), 30 pages. Read online or download the free PDF. - Page: https://www.hlayiso.com/library/electrical-technology-may-june-2022-electronics-eng/ac330f84-e797-4bbd-9b67-7c458869999e - Updated: 2026-09-27 - Subject: Electrical Technology - Grade: Grade 12 - Document type: Question paper - Year: 2022 - Exam period: NSC June Exam - Curriculum: CAPS - Pages: 30 Breadcrumbs: [Home](https://www.hlayiso.com/) › [Library](https://www.hlayiso.com/library) › [Grade 12](https://www.hlayiso.com/library/grade-12) › [Electrical Technology](https://www.hlayiso.com/library/grade-12/electrical-technology) › [Electrical Technology Grade 12 NSC June 2022 QP (Eng)](https://www.hlayiso.com/library/electrical-technology-may-june-2022-electronics-eng/ac330f84-e797-4bbd-9b67-7c458869999e) ## About this document Electrical Technology · Grade 12 · NSC June Exam · 2022. Question paper, 30 pages. Read online or download the PDF. Read it free online on the page above; download the PDF from there. ## Document text Text extracted from the PDF. Layout, diagrams and tables may not survive extraction. ### Page 1 Downloaded from hlayiso.com SENIOR CERTIFICATE EXAMINATIONS/ NATIONAL SENIOR CERTIFICATE EXAMINATIONS ELECTRICAL TECHNOLOGY: ELECTRONICS 2022 MARKS: 200 TIME: 3 hours This question paper consists of 25 pages, a 1-page formula sheet and 4 answer sheets. Copyright reserved Please turn over ### Page 2 Downloaded from hlayiso.com Electrical Technology: Electronics 2 DBE/2022 SC/NSC INSTRUCTIONS AND INFORMATION 1. This question paper consists of SIX questions. 2. Answer ALL the questions. 3. Answer the following questions on the attached ANSWER SHEETS: QUESTIONS 4.2.1, 4.2.2, 4.3.3 and 4.7.3 QUESTIONS 5.3.5, 5.4.6, 5.6.1 and 5.6.2 QUESTION 6.5.3 4. Write your centre number and examination number on every ANSWER SHEET and hand them in with your ANSWER BOOK, whether you have used them or not. 5. Sketches and diagrams must be large, neat and FULLY LABELLED. 6. Show ALL calculations and round off answers correctly to TWO decimal places. 7. Number the answers correctly according to the numbering system used in this question paper. 8. You may use a non-programmable calculator. 9. Calculations must include: 9.1 Formulae and manipulations where needed 9.2 Correct replacement of values 9.3 Correct answers and relevant units where applicable 10. A formula sheet is attached at the end of this question paper. 11. Write neatly and legibly. Copyright reserved Please turn over ### Page 3 Downloaded from hlayiso.com Electrical Technology: Electronics 3 DBE/2022 SC/NSC QUESTION 1: MULTIPLE-CHOICE QUESTIONS Various options are provided as possible answers to the following questions. Choose the answer and write only the letter (AD) next to the question numbers (1.1.1 to 1.1.15) in the ANSWER BOOK, e.g. 1.16 D. 1.1 The layer(s) of the skin that is/are affected by a third-degree burn would be … A the outer layer. B the second layer. C all layers of the skin. D None of the above-mentioned (1) 1.2 The power factor in an RLC series circuit will be lagging if VL … A is greater than VC. B is less than VC. C is equal to VC. D None of the above-mentioned (1) 1.3 A circuit has a resistance of R ohm, inductance of L henry and a capacitance of C farad connected in series. The power factor of the circuit will be at unity (1) when … A XL is less than XC. B XL is greater than XC. C XL = XC. D R = 0. (1) 1.4 Which ONE of the following conditions exists in a resonant parallel RLC circuit? A The impedance is minimum. B The impedance is maximum. C The total current is maximum. D The power factor is lagging. (1) 1.5 The … is a device that relies on the creation of an electric field within the channel to control current flow. A Darlington pair transistor B unijunction transistor C field-effect transistor D operational amplifier (1) Copyright reserved Please turn over ### Page 4 Downloaded from hlayiso.com Electrical Technology: Electronics 4 DBE/2022 SC/NSC 1.6 When applying a signal to the inverting input of an op amp, phase shift is achieved by the … A cut-off frequency. B internal amplifier circuits. C notch frequency. D unity-gain frequency. (1) 1.7 Negative feedback in an op amp … A increases the input and output impedances. B decreases the output impedance and the bandwidth. C increases the input impedance and the bandwidth. D does not affect impedances or the bandwidth. (1) 1.8 Open-loop gain with reference to op amps is when … A a feedback resistor is connected from the output to the inverting input. B no feedback resistor is connected from the output to the input. C a capacitor is connected from the output to the inverting input. D a feedback resistor is connected from the output to the non-inverting input. (1) 1.9 When a triangular waveform is applied to the input of a differentiator, the output waveform will be a/an … A DC level. B inverted triangular waveform. C first harmonic frequency of the triangular waveform. D square waveform. (1) 1.10 The basic circuit of a passive RC differentiator is a … A capacitor in series with the input and a resistor in parallel with the output. B resistor in series with the input and a capacitor in parallel with the output. C resistor in series with the input and a resistor in parallel with the output. D capacitor in series with the input and a capacitor in parallel with the output. (1) Copyright reserved Please turn over ### Page 5 Downloaded from hlayiso.com Electrical Technology: Electronics 5 DBE/2022 SC/NSC 1.11 A/An … circuit is used to clean up an input signal which has been distorted. A integrator B differentiator C Schmitt trigger D comparator (1) 1.12 In a class C amplifier, the output collector current will flow through the transistor for … of the input cycle. A more than 180⁰ B 90⁰ C 360⁰ D less than 180⁰ (1) 1.13 The operation of a relaxation oscillator is based on … A the charging and discharging of a capacitor. B a highly selective resonant circuit. C a very stable supply voltage. D lower power consumption. (1) 1.14 For an oscillator to maintain oscillation, the gain must be … A 1. B less than 1. C greater than 1. D equal to β. (1) 1.15 A bipolar junction transistor class B push-pull amplifier with no transformer coupling uses … A two NPN transistors. B two PNP transistors. C one NPN transistor. D complementary symmetrical transistors. (1) [15] Copyright reserved Please turn over ### Page 6 Downloaded from hlayiso.com Electrical Technology: Electronics 6 DBE/2022 SC/NSC QUESTION 2: OCCUPATIONAL HEALTH AND SAFETY 2.1 Explain the term machinery with reference to the Occupational Health and Safety Act, 1993 (Act 85 of 1993). (2) 2.2 Explain the term critical incident with regard to emergencies. (2) 2.3 State TWO steps you should take when you discover a fire in an electrical workshop. (2) 2.4 State the importance of wearing a face mask in the workshop. (2) 2.5 Name TWO environmental considerations when working with chemicals during the printed circuit board manufacturing process. (2) [10] Copyright reserved Please turn over ### Page 7 Downloaded from hlayiso.com Electrical Technology: Electronics 7 DBE/2022 SC/NSC QUESTION 3: RLC CIRCUITS 3.1 Define a phasor diagram with reference to RLC circuits connected across an alternating voltage supply. (2) 3.2 FIGURE 3.2 below shows an RLC series circuit which consists of a resistor with a resistance of 10 Ω, an inductor with an inductive reactance of 14 Ω and a capacitor with a capacitive reactance of 8 Ω, all connected across an alternating supply of 100 Hz. R = 10 Ω XL = 14 Ω XC = 8 Ω 150 V 180 V 90 V 100 Hz FIGURE 3.2: SERIES RLC CIRCUIT Given: R = 10 Ω XC = 8Ω XL = 14 Ω VR = 150 V VL = 180 V Vc = 90 V f = 100 Hz 3.2.1 Calculate the total supply voltage applied to the circuit. (3) 3.2.2 Discuss whether the power factor will be leading or lagging. (3) Copyright reserved Please turn over ### Page 8 Downloaded from hlayiso.com Electrical Technology: Electronics 8 DBE/2022 SC/NSC 3.3 Refer to FIGURE 3.3 below and answer the questions that follow. C IC = 4 A L IL = 6 A IR = 4 A R IT AC Supply FIGURE 3.3: PARALLEL RLC CIRCUIT Given: Ic = 4A IL = 6A IR = 4A 3.3.1 Calculate the total current. (3) 3.3.2 Calculate the phase angle. (3) 3.3.3 Draw the phasor diagram for FIGURE 3.3. (4) 3.3.4 Motivate with a reason if the circuit is predominately capacitive or inductive. (2) Copyright reserved Please turn over ### Page 9 Downloaded from hlayiso.com Electrical Technology: Electronics 9 DBE/2022 SC/NSC 3.4 Refer to FIGURE 3.4 below and answer the questions that follow. V = 600 V R = 2,2 k Ω L = 10 mH XC = 150 Ω fr = 2,387 kHz FIGURE 3.4: RESONANT RLC CIRCUIT 3.4.1 Calculate the quality factor of the circuit. (3) 3.4.2 Calculate the bandwidth. (3) 3.4.3 Calculate the value of the capacitor. (3) 3.4.4 Define the term selectivity with reference to resonant circuits. (2) 3.5 Refer to FIGURE 3.5 below and answer the questions that follow. P +V +V V V Average I power I 00 t 00 t o 180o 270o o 180 o o 90 360o 90 360 -V -V (A) (B) FIGURE 3.5: CURRENT, VOLTAGE AND POWER WAVEFORMS 3.5.1 State with a reason the type of component that produces the waveform in FIGURE 3.5 (A). (2) 3.5.2 Identify the component across which power is dissipated in FIGURE 3.5 (B). Motivate your answer. (2) [35] Copyright reserved Please turn over ### Page 10 Downloaded from hlayiso.com Electrical Technology: Electronics 10 DBE/2022 SC/NSC QUESTION 4: SEMICONDUCTORS 4.1 Draw a fully labelled IEC symbol of a unijunction transistor. (3) 4.2 Refer to FIGURE 4.2 below and answer the questions that follow. ID(mA) ID(mA) (V) -6 + VDS -5 -4 -3 -2 -1 Transfer characteristic Output characteristic FIGURE 4.2: TRANSFER CHARACTERISTIC OF JFET 4.2.1 Draw a fully labelled output characteristic curve of the n-channel junction field-effect transistor (JFET) for the given transfer characteristic shown in FIGURE 4.2 on the ANSWER SHEET for QUESTION 4.2.1. (3) 4.2.2 On the ANSWER SHEET for QUESTION 4.2.2, indicate the pinch-off voltage on the output characteristic curve if VGS = -1 V. (1) Copyright reserved Please turn over ### Page 11 Downloaded from hlayiso.com Electrical Technology: Electronics 11 DBE/2022 SC/NSC 4.3 Refer to FIGURE 4.3 below and answer the questions that follow. VDD R1 RD C2 Vout D C1 Vin G S RL R2 RS 0V FIGURE 4.3: AMPLIFIER CIRCUIT DIAGRAM 4.3.1 Identify the amplifier circuit diagram in FIGURE 4.3. (2) 4.3.2 Describe how the circuit will be able to amplify the input signal as a linear amplifier. (3) 4.3.3 Complete the input transfer characteristic curve of the circuit diagram in FIGURE 4.3 by using the information provided on the ANSWER SHEET for QUESTION 4.3.3. (3) Copyright reserved Please turn over ### Page 12 Downloaded from hlayiso.com Electrical Technology: Electronics 12 DBE/2022 SC/NSC 4.4 Refer to FIGURE 4.4 below and answer the questions that follow. + 9V LED R1 = 100 kΩ R2 = 300 Ω S1 C B E 0V FIGURE 4.4: TRANSISTOR CIRCUIT DIAGRAM 4.4.1 Identify the application of the transistor circuit diagram in FIGURE 4.4. (1) 4.4.2 Briefly describe the operation of the circuit when the switch is closed. (3) 4.5 Refer to FIGURE 4.5 below and answer the questions that follow. R F = 3 kΩ R IN = 100 Ω + 15 V _ + VOUT 0 V - 15 V FIGURE 4.5: INVERTING OP AMP 4.5.1 State why the circuit is called an inverting op amp. (1) 4.5.2 Explain how the gain of the op amp is controlled. (2) 4.5.3 Calculate the gain of the op amp. (3) Copyright reserved Please turn over ### Page 13 Downloaded from hlayiso.com Electrical Technology: Electronics 13 DBE/2022 SC/NSC 4.6 FIGURE 4.6 below shows the 555 IC. Answer the questions that follow. 0V 1 8 +Vcc TRIGGER 2 7 DISCHARGE 555 IC OUTPUT 3 6 THRESHOLD CONTROL RESET 4 5 VOLTAGE FIGURE 4.6: 555 IC PIN LAYOUT 4.6.1 Briefly describe the functions of pin 6 with reference to the 555 IC. (3) 4.6.2 State the supply voltage range at which the 555 IC operates. (2) 4.6.3 Explain the function of the SR flip-flop in the internal circuit of the 555 timer. (2) Copyright reserved Please turn over ### Page 14 Downloaded from hlayiso.com Electrical Technology: Electronics 14 DBE/2022 SC/NSC 4.7 Refer to FIGURE 4.7 below and answer the questions that follow. Vcc = +5 V to 15 V R1 R2 8 4 Vout 7 3 555 IC 6 1 2 0 5 1 Trigger Input C1 C = 0,01 µF (S1) 0V FIGURE 4.7: 555 IC MULTIVIBRATOR 4.7.1 Identify the multivibrator in FIGURE 4.7. (1) 4.7.2 Give a brief description of what happens when the push-to-make switch (S1) is activated. (4) 4.7.3 Draw on the ANSWER SHEET for QUESTION 4.7.3 the voltage waveform of the capacitor C1 and the output voltage waveform when the trigger input is pressed. (4) Copyright reserved Please turn over ### Page 15 Downloaded from hlayiso.com Electrical Technology: Electronics 15 DBE/2022 SC/NSC 4.8 Refer to FIGURE 4.8 below which has an output frequency of 1 hertz and answer the questions that follow. 9V R1 4 8 7 3 Vout 555 f = 1 Hz R2 R3 6 2 1 5 LED C1 C2 0V FIGURE 4.8: ASTABLE MULTIVIBRATOR 4.8.1 Explain the mode (state) of the LED. (2) 4.8.2 Explain the effect on the LED when: (a) R2 is halved (1) (b) The value of C1 is doubled (1) [45] Copyright reserved Please turn over ### Page 16 Downloaded from hlayiso.com Electrical Technology: Electronics 16 DBE/2022 SC/NSC QUESTION 5: SWITCHING CIRCUITS 5.1 Name the type of multivibrator that: 5.1.1 Produces one pulse cycle of 'high' and 'low' when a trigger pulse is applied to its input (1) 5.1.2 Changes state when a trigger pulse is applied and remains in that state (1) 5.2 Refer to FIGURE 5.2 below and answer the questions that follow. +9V R2 R1 10 kΩ 10 kΩ R3 4 8 470 Ω 7 555 3 6 2 1 5 LED Set Reset C1 10 nF FIGURE 5.2: BI-STABLE MULTIVIBRATOR 5.2.1 Name the function of resistors: (a) R1 (1) (b) R3 (1) 5.2.2 Identify the state of the LED when trigger pin 2 is high. (1) 5.2.3 Explain what happens in the circuit when the set switch is pressed. (2) 5.2.4 Explain the purpose of connecting pin 6 to ground. (2) Copyright reserved Please turn over ### Page 17 Downloaded from hlayiso.com Electrical Technology: Electronics 17 DBE/2022 SC/NSC 5.3 FIGURE 5.3 below shows an op amp as a comparator. The resistance of the LDR increases as the level of light falls. +V R1 V Vin 100 kΩ R3 V in Vref 1 kΩ 741 t R2 100 kΩ LED 2 LDR LED 1 white red 0V -V FIGURE 5.3: OP AMP COMPARATOR AS A DARK SENSOR 5.3.1 State the purpose of R2. (1) 5.3.2 Explain how an increase in the level of light affects the voltage on the non-inverting input. (2) 5.3.3 Explain the operation of the circuit with reference to the voltages on the input terminals and the output voltage. (3) 5.3.4 Predict the state of LED1 and LED2 when the voltage on the inverting terminal is higher than the voltage on the non-inverting terminal. (2) 5.3.5 Draw the output on the ANSWER SHEET for QUESTION 5.3.5. (3) Copyright reserved Please turn over ### Page 18 Downloaded from hlayiso.com Electrical Technology: Electronics 18 DBE/2022 SC/NSC 5.4 Refer to FIGURE 5.4 below and answer the questions that follow. VIN +10 V V 0 t VOUT RF -10 V 9 kΩ 1V 0 t R1 -1 V 1 kΩ 0V FIGURE 5.4: SCHMITT TRIGGER 5.4.1 Identify the type of Schmitt trigger circuit. (1) 5.4.2 Determine the value of the output voltage when the voltage on the non-inverting input is -1 V. (1) 5.4.3 State whether this circuit uses positive or negative feedback. (1) 5.4.4 Explain the operation of the circuit with reference to the input and trigger voltage levels. (4) 5.4.5 Predict how an increase in the value of R1 will affect the trigger voltage level. (1) 5.4.6 Draw the output signal on the ANSWER SHEET for QUESTION 5.4.6. (4) Copyright reserved Please turn over ### Page 19 Downloaded from hlayiso.com Electrical Technology: Electronics 19 DBE/2022 SC/NSC 5.5 Refer to FIGURE 5.5 below and answer the questions that follow. RF 100 kΩ C1 R1 10 kΩ 0,4 V C2 R2 10 kΩ +9 V 0,5 V - C3 R3 10 kΩ + 0,25 V VOUT -9 V 0V FIGURE 5.5: SUMMING AMPLIFIER 5.5.1 The variable resistor RF serves a dual purpose. Name both purposes. (2) 5.5.2 Calculate the output voltage when the value of RF is set to 78,26 kΩ. (3) 5.5.3 Explain how an increase in the value of RF affects the gain of the amplifier. (1) 5.5.4 Describe why it is not recommended to increase the value of RF beyond 78,26 kΩ. (4) 5.5.5 Explain how this limitation can be overcome without changing the value of any of the resistors. (2) 5.6 Refer to FIGURE 5.6 below and answer the questions that follow. V R 1 kΩ Input VIN VOUT t Vsupply C Output 10 µF t FIGURE 5.6: PASSIVE RC INTEGRATOR 5.6.1 Draw the output when the value of C is changed to 1 µF on the ANSWER SHEET for QUESTION 5.6.1. (3) 5.6.2 Draw the output when the value of C is changed to 100 µF on the ANSWER SHEET for QUESTION 5.6.2. (3) [50] Copyright reserved Please turn over ### Page 20 Downloaded from hlayiso.com Electrical Technology: Electronics 20 DBE/2022 SC/NSC QUESTION 6: AMPLIFIERS 6.1 Describe the term linear amplifier with reference to amplifiers. (2) 6.2 Name ONE consideration when determining the amplifier class. (1) 6.3 Refer to FIGURE 6.3 below and answer the questions that follow. IC (mA) 12 10 Q1 8 A IB = 500 µA 6 IB = 400 µA Q2 4 IB = 300 µA 2 IB = 200 µA Q3 IB = 100 µA B VCE 2 4 6 8 10 12 (V) FIGURE 6.3: DC LOAD LINE 6.3.1 In which region (A or B) does the saturation point of the biased transistor occur? (1) 6.3.2 At which Q-point would class AB amplifiers be represented along the DC load line? (1) 6.3.3 Name ONE condition that affects the quiescent voltages and quiescent currents at Q3. (1) 6.4 Briefly explain how class B amplifiers operate. (2) Copyright reserved Please turn over ### Page 21 Downloaded from hlayiso.com Electrical Technology: Electronics 21 DBE/2022 SC/NSC 6.5 Refer to FIGURE 6.5 below and answer the questions that follow. Stage 1 Stage 2 + VCC R1 R C1 C2 R3 RC2 C3 C1 Q1 Q2 AC RL Input CE1 CE2 R2 R E1 R4 RE2 0V FIGURE 6.5: TWO-STAGE RC-COUPLED AMPLIFIER 6.5.1 State the purpose of using multi-stages in amplifiers. (1) 6.5.2 Calculate the total voltage gain in decibel of the circuit diagram if stage 1 has a voltage gain of 10 and stage 2 has a voltage gain of 15. (5) 6.5.3 Draw the output waveform across the load on the ANSWER SHEET for QUESTION 6.5.3. (3) Copyright reserved Please turn over ### Page 22 Downloaded from hlayiso.com Electrical Technology: Electronics 22 DBE/2022 SC/NSC 6.6 Refer to FIGURE 6.6 below and answer the questions that follow. + VCC T1 T2 R1 Matching R3 transformer Matching transformer Q1 Q2 C2 R2 R E1 C1 R4 R E2 C3 0V FIGURE 6.6: TRANSFORMER COUPLED AMPLIFIER 6.6.1 State the function of capacitor (C2) connected across resistor R4. (2) 6.6.2 Name ONE advantage of a transformer coupled amplifier. (1) 6.6.3 Explain why it is preferable to connect the load via an output transformer (T2). (2) Copyright reserved Please turn over ### Page 23 Downloaded from hlayiso.com Electrical Technology: Electronics 23 DBE/2022 SC/NSC 6.7 Refer to FIGURE 6.7 below and answer the questions that follow. +VCC T2 R1 C1 C2 Output T1 Q1 Input R2 C3 R2 CE 0V FIGURE 6.7: AMPLIFIER CIRCUIT DIAGRAM 6.7.1 Identify the amplifier in FIGURE 6.7. (1) 6.7.2 Describe the basic operation of the amplifier circuit. (2) 6.7.3 Give a reason why capacitor C2 is connected across the secondary coil of transformer T2. (2) 6.8 The power of an amplifier is 200 mW at a frequency of 20 kHz. When the frequency increases to 30 kHz, the power decreases to 100 mW. Calculate the power loss of the system in decibel. (3) Copyright reserved Please turn over ### Page 24 Downloaded from hlayiso.com Electrical Technology: Electronics 24 DBE/2022 SC/NSC 6.9 Refer to FIGURE 6.9 below and answer the questions that follow. + VCC R1 RF choke C3 C6 C4 Q1 C1 R2 R3 C5 L 0V C2 FIGURE 6.9: OSCILLATOR CIRCUIT DIAGRAM 6.9.1 Identify the oscillator circuit diagram in FIGURE 6.9. (1) 6.9.2 Briefly describe the function of the: (a) Amplifier circuit (2) (b) Tank circuit (2) 6.9.3 Explain why the feedback network (RF choke and C3) is regarded as a filter. (2) Copyright reserved Please turn over ### Page 25 Downloaded from hlayiso.com Electrical Technology: Electronics 25 DBE/2022 SC/NSC 6.10 Refer to FIGURE 6.10 of an RC-phase shift oscillator and answer the questions that follow. +VCC RB RC C5 VOUT C1 C2 C3 Q1 R1 R2 R3 R4 C4 0V FIGURE 6.10: RC-PHASE SHIFT OSCILLATOR 6.10.1 State ONE function of R3. (1) 6.10.2 Describe how the RC-phase shift oscillator achieves its phase shift of 360⁰ during its operation. (4) 6.10.3 Calculate the oscillation frequency of the oscillator circuit if R1 = R2 = R3 =10 kΩ and C1= C2= C3 = 0,001 µF. (3) [45] TOTAL: 200 Copyright reserved ### Page 26 Downloaded from hlayiso.com Electrical Technology: Electronics DBE/2022 SC/NSC FORMULA SHEET RLC CIRCUITS SEMICONDUCTOR DEVICES P  V  I  cos θ V R RF Gain A V  OUT   F AV  1 XL  2 fL VIN RIN RIN 1  R  XC  VOUT  VIN    F  2 fC  R IN  fr  1 OR fr  f2  f1  R  2 LC 2 VOUT  VIN  1  F  fr  R IN  BW  OR BW  f2  f1 Q SWITCHING CIRCUITS SERIES  R R R  VOUT    V1 F  V2 F  ...VN F  VR  I R  R1 R2 RN  VL  I XL VOUT VOUT Gain A V   VC  I XC VIN V1  V2  ...VN  VT IT  IR  IC  IL VOUT   (V1  V2  ...VN ) IT  OR Z AMPLIFIERS V Z  R 2  X L  X C  2 IC  C VCC  VCE  ICRC RC VT  VR  VL  VC  VT  I Z VB  VBE  VRE 2 2 OR R VR VOUT Cos θ  OR Cos θ  AV  Z VT VIN XL X C VL VC 1 L I Q     A I  OUT R R VT VT R C IIN PARALLEL P A P  OUT AP  A V A I VT  VR  VL  VC PIN OR VT IR  βT = β 1 x β 2 OR A VT  A V1  A V2  A V3  ...A Vn R VT IC  PIN  I2  ZIN POUT  I2  Z OUT XC AND V OSCILLATION FREQUENCY IL  T 1 1 XL fo  OR fo  2  π LC 2  π 6 RC IT  IR  IL  IC  2 2 GAIN IN DECIBELS VT I Z A I  20log10 OUT IT IIN I Cos θ  R A V  20log10 VOUT OR A V  20log 10 A VT IT VIN R R POUT P Q  A P  10log10 OR A P  10log10 2 XL X C PIN P1 Copyright reserved ### Page 27 Downloaded from hlayiso.com Electrical Technology: Electronics DBE/2022 SC/NSC CENTRE NUMBER: EXAMINATION NUMBER: ANSWER SHEET QUESTION 4: SEMICONDUCTORS 4.2.1 ID(mA) ID(mA) and 4.2.2 (V) -6 + VDS -5 -4 -3 -2 -1 Transfer characteristic Output characteristic Transfer mark to Transfer mark to answer book answer book MOD MOD (4.2.1) (4.2.2) FIGURE 4.2 (4) 4.3.3 ID(max) Transfer mark to ID Q answer book VGS MOD VQ VGS FIGURE 4.3.3 (3) Copyright reserved ### Page 28 Downloaded from hlayiso.com Electrical Technology: Electronics DBE/2022 SC/NSC CENTRE NUMBER: EXAMINATION NUMBER: ANSWER SHEET 4.7.3 V Trigger t input Capacitor voltage t Transfer mark to answer book Output voltage MOD t FIGURE 4.7.3 (4) QUESTION 5: SWITCHING CIRCUITS 5.3.5 Vin V Vref Input t Vsat Transfer mark to answer book Output MOD t FIGURE 5.3.5 (3) Copyright reserved ### Page 29 Downloaded from hlayiso.com Electrical Technology: Electronics DBE/2022 SC/NSC CENTRE NUMBER: EXAMINATION NUMBER: ANSWER SHEET 5.4.6 +V Upper trigger voltage 0 Lower trigger voltage -V +Vsat 0 Transfer mark to answer book MOD -Vsat FIGURE 5.4.6 (4) 5.6.1 V Input t Vsupply Transfer mark to answer book Output t MOD FIGURE 5.6.1 (3) Copyright reserved ### Page 30 Downloaded from hlayiso.com Electrical Technology: Electronics DBE/2022 SC/NSC CENTRE NUMBER: EXAMINATION NUMBER: ANSWER SHEET 5.6.2 V Input t Vsupply Transfer mark to answer book Output t MOD FIGURE 5.6.2 (3) QUESTION 6: AMPLIFIERS 6.5.3 +V Input 0 t -V +V Output 0 t Transfer mark to answer book -V MOD FIGURE 6.5.3 (3) Copyright reserved ## Related documents - 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