Title Copy of T790 - INDUSTRIAL ELECTRONICS N5 NOV QP 2022.pdf ✅

Copyright reserved Please turn over NATIONAL CERTIFICATE INDUSTRIAL ELECTRONICS N5 (8080175) 21 November 2022 (X-paper) 09:00–12:00 Drawing instruments and nonprogrammable calculators may be used. This question paper consists of 5 pages and a formula sheet of 6 pages. 108Q1E2221
(8080175) -2 Copyright reserved Please turn over DEPARTMENT OF HIGHER EDUCATION AND TRAINING REPUBLIC OF SOUTH AFRICA NATIONAL CERTIFICATE INDUSTRIAL ELECTRONICS N5 TIME: 3 HOURS MARKS: 100 INSTRUCTIONS AND INFORMATION 1. 2. 3. 4. 5. 6. 7. 8. 9. Answer all the questions. Read all the questions carefully. Number the answers according to the numbering system used in this question paper. ALL the calculations must be shown. ALL the sketches and diagrams must be large, clear and neat. Keep questions and subsections of questions together. Use only a black or blue pen. Start each question on a new page. Write neatly and legibly.
(8080175) -3 Copyright reserved Please turn over QUESTION 1: ALTERNATING CURRENT THEORY 1.1 In a serial RL circuit it takes 2 s for the circuit to reach 63,2% of the total current IT. If R = 150 k and VT = 5 V, calculate: 1.1.1 1.1.2 The value of L IL after 2 s (2) (3) 1.2 Draw a neat, labelled circuit diagram of an RC integrator as well as the frequency response curve thereof. (3) 1.3 A circuit consists of the following components: Z1 = 120 ‒j 21,21 Ω Z2 = 180 +j 25,31 Ω Z3 = 100 +j 47,31 Ω All impedances are connected in parallel and to a 250 V/50 Hz supply. Calculate the total impedance of the circuit. (9) [17] QUESTION 2: POWER SUPPLIES 2.1 Calculate the value of the series resistor needed in order to protect a Zener diode that has 750 mW, 12 V in a voltage reference source. The circuit is supplied with the maximum voltage of 20 V. (4) 2.2 Draw a neat, labelled circuit diagram of a parallel voltage regulator and briefly describe its operation. (7) 2.3 Show, with the aid of a neat, labelled circuit diagram, how a 5 V fixed voltage regulator can be used to produce a voltage lower than a fixed voltage regulator. (5) [16]  
(8080175) -4 Copyright reserved Please turn over QUESTION 3: TRANSISTOR AMPLIFIERS 3.1 The following information about a common emitter amplifier is known: Ve = 1,5V; B = 40μA; Rc =750 ;  = 250; Re = 120; Vb = 0,6V 3.1.1 Vce (5) 3.1.2 Rb1 and Rb2 (4) 3.2 A fixed-bias voltage amplifier has an input impedance of 2 k and an output impedance of 2,5 k. Calculate the values of the collector resistor and base resistor with the precise method if the following information about the transistor is known: hie = 12k; hre = 2  10-4; hfe = 100; and hoe = 20A/V RS = 0 (8) [17] QUESTION 4: OPERATIONAL AMPLIFIERS 4.1 Explain the term common-mode rejection ratio. (2) 4.2 If the input signal is a square waveform of ± 1 V, 500 Hz and the input resistor and feedback capacitor have values of 10 M and 0,01 μF respectively, calculate the output voltage and draw its waveform (the capacitor is initially discharged). (9) [11] QUESTION 5: INTEGRATED CIRCUITS 5.1 Name FOUR types of voltage regulators. (4) 5.2 Explain the term static electricity. (2) [6]   