Electrical Technology Midterm Exam 2023-2024 PDF

Misr International Technological University Executing and Putting Into Operation Technical Building Services Systems (‫)تنفيذ وتشغيل أنظمة الخدمات الفنية للمباني‬ Egyptian-German collage of Technology in Assiut...

Misr International Technological University Executing and Putting Into Operation Technical Building Services Systems (‫)تنفيذ وتشغيل أنظمة الخدمات الفنية للمباني‬ Egyptian-German collage of Technology in Assiut Course code: E1ITCE02 Electrical Technology 1st year, Bylaw 2021 1st Semester - Midterm Exam Time: 1h:30m 2023/2024 - Dec. 2023 Marks: 60 ---------------------------------------------------------------------------------------------------- Important 1. No of pages: 3 pages Remarks 2. No of questions: 2 Answer all questions :)‫االسم (رباعي بالعربي‬ Question No. 1: √ (True) or X (False) (20 marks/1 mark each). 1. Electricity network consists of three stages: generation, transmission and distribution. √ 2. The direct current (DC) is varied with time. X 3. The alternative current (AC) alternates between positive and negative values. √ 4. The current and voltage at our homes are DC type. X 5. It is not possible to convert AC to DC. X 6. It possible to step-up or step-down the DC voltage by using the transformer. X 7. The electric cable consists of conductor and insulator. √ 8. It is preferable to install the cables with different voltages in the same pipe. X 9. The 36 mm2 pipes is used to lighting and sockets (outlets) network. X 10. If the current passing in the fuse is less than the rated current the fuse will open the circuit. X 11. Melting time of the fuse is less than its operating time. √ 12. By increasing the current passing in the fuse, the operating time of the fuse is decreases. √ 13. At the end of melting time of fuse, the current in the circuit is zero. X 14. The fuse element of the fuse is made of PVC. X 15. Luminous Flux is the light energy radiated out per second from the body in the form of luminous light waves. √ 16. Luminous Intensity (I) is luminous flux radiated out per unit surface area. X 17. The illumination (E) of a surface is measured by the normal luminous flux per unit area received by it. √ 18. The unit of the efficacy of the light is Lm/W. √ 19. The Lux is the unit of Illumination. √ 20. The most common measure of light output (or luminous flux) is the watt. X 2023/2024 Page | 1  Answer Here 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 √ X √ X X X √ X X X √ √ X X √ X √ √ √ X Question No. 2: Choose the correct answer (40 marks/2 marks each). 1. Generation plants such as: (a) solar power plants (b) nuclear plants (c) hydraulic power plants (d) all are correct 2. The waveform of AC current or voltage can be: (a) sine (b) triangle (c) square (d) all are correct 3. The frequency at our home is: (a) 50kHz (b) 60Hz (c) 50 Hz (d) all are correct 4. A 100kV cable is considered ….. cable: (a) Ultra-high voltage (b) low voltage (c) medium voltage (d) high voltage 5. The most common type of insulators is: (a) Oil cables (b) PVC (c) X.L.P.E (d) E.P.R. 6. The most expensive type of insulators is: (a) Oil cables (b) PVC (c) X.L.P.E (d) E.P.R. 7. The insulator which withstanding high temperature and chemically inactive is: (a) Oil cables (b) PVC (c) X.L.P.E (d) E.P.R. 8. In single phase system, the color of earthing cable is: (a) Red (b) green-and-yellow (c)black (d) blue 9. In single phase system, the color of phase conductor (line) cable is: (a) Red (b) yellow (c)blue (d) all are correct 10. The flexible hose-pipe is used to: (a) long ceiling (b) vertical feeding (c) connectors and junction (d) decoration works 11. The fuse in the circuit is connected: (a) before the source (b) after the load (c) between source and load (d) all are correct 12. If the rated current of fuse is 10 A, the interrupting rate could be: (a) 10 A (b) 30 A (c) 8 A (d) all are correct 2023/2024 Page | 2  13. The fuse in the circuit should be connected in: (a) series (b) parallel (c) shunt (d) all are correct 14. The gG type fuse is used for: (a) motors (b) electronic circuits (c) lighting circuits (d) all are correct 15. The fuse element is made of: (a) copper (b) silver (c) aluminium (d) all are correct 16. The element which is used to extinguish the electric arc in the fuse is: (a) fuse contact points (b) fuse element (c) fuse link (d) all are correct 17. The fuse can withstand overload current higher than rated load current by: (a) 30% (b) 10% (c) 50% (d) all are correct 18. If the short circuit current exceeds the rupture capacity of the fuse: (a) fuse will open (b) fuse will explode and damage (c) no-action will happen (d) all are correct 19. Illumination is measured by: (a) Lemen (b) Watt (c) Lm/m2 (d) all are correct 20. The color rendering index (CRI) of the LED lamps is: (a) 105% (b) 1.12 (c) 90% (d) all are correct Answer Here 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 d d C d b C C b d a C b a C d C b b C C --------------------------------------------------End-------------------------------------------------------- Best wishes Examiner's committee: Dr. Ahmed Elnozahy 2023/2024 Page | 3