STED COUNCIL ELECTRICAL QA\QC 2022 SCHEME STED COUNCIL (QA/QC) Online Exam 1 / 50 Transformer ratings are given in kVAR HP kVA KW 2 / 50 A series motor is best suited for driving shear and punches cranes and hoists none of the above machine tools 3 / 50 Which of the following circuit element stores energy in the electromagnetic field variable resistor condenser inductance resistance 4 / 50 How much current is produced by a voltage of 18kV across a 15-kilo ohm resistance? 12mA 1.2A 120mA 12A 5 / 50 Starters are used with D.C motors because These motors have high starting torque These motors are not self-starting Back emf of these motors is initially zero To restrict armature current as there is no back emf while starting 6 / 50 The algebraic sum of voltages around any closed path in a network is equal to negative polarity 0 1 infinity 7 / 50 Fuse protection is used for current ratings up to 20A 100A 50A 10A 8 / 50 Relation between phase voltage and line voltage in three phase delta connected system Vline= Vphase Vline= Vphase/1.73 Vline= 1.41Vphase Vline= 1.73Vphase 9 / 50 The operating voltage of high-tension cables is up to 66kV 6.6kV 11kV 33kV 10 / 50 The chemical used in breather for transformer should have the quality of ionizing air cleansing the transformer oil cooling the transformer oil absorbing moisture 11 / 50 Who typically performs Factory Acceptance Testing Developers End- users or stakeholders Testers Project Managers 12 / 50 Laminated core in electrical machines are used to reduce eddy current loss hysteresis loss copper loss all of the above 13 / 50 Moisture content in the soil earth soil resistance decrease none of the above increase does not affect 14 / 50 The material commonly used for sheath of underground cables is Copper Rubber Iron Lead 15 / 50 A 3phase squirrel cage induction motor is started with star delta starter. What is the starting current of the motor 1/6 times the current with DOL 3 times the starting current with DOL None of the above 1/3 times the current with DOL 16 / 50 A 3-phase 4-wire system is commonly used on Secondary transmission Secondary distribution Primary distribution Primary transmission 17 / 50 Sag is independent of None of the above tension in the conductor line voltage length of span 18 / 50 For 66Kv lines the number of insulator disc are used 8 10 2 6 19 / 50 The wooden poles well impregnated with creosote oil or any preservative compound have life 60 to 70 years 25 to 30 years 10 to 15 years 2 to 5 years 20 / 50 What is QA it is a corrective tool it is the measurement of degree to which a product satisfies the need any systematic process used to ensure quality in the process process of identifying defects 21 / 50 Permissible current density of GI .28A/mm2 1.2A/mm2 118A/mm2 48A/mm2 22 / 50 How much module box required for a single switch and socket 1m 3m 4m 6m 23 / 50 Differential relays use the principle of Frequency domain analysis Current magnitude comparison between incoming and outgoing feeder Time domain comparison 24 / 50 What is the standard size of GI earth wire in domestic installation 8 SWG 10 SWG 12 SWG 14 SWG 25 / 50 Form factor for a sine wave is 1.414 0.637 0.707 1.11 26 / 50 The frequency of domestic power supply in India is 60 Hz 50 Hz 200 Hz 100 Hz 27 / 50 The voltage of the single-phase supply to residential consumer is 210V 230V 400V 110V 28 / 50 The primary winding of a transformer has a 120V ac supply. What is the value of secondary voltage if the turns ratio is 10 120V 12000V 12V 1200V 29 / 50 Distribution lines in India generally use Wooden poles None of the above Steel towers R.C.C poles 30 / 50 Size of wire required for a.c 2.5sqm 1.5sqm 1sqm 4sqm 31 / 50 The operating voltage of extra high-tension cables is up to 6.6kV 66kV 11kV 33kV 32 / 50 Which type of wiring system is suitable for multistorey building Tree system looping out with junction box distribution board system Ring main system 33 / 50 Lamination of transformer core is made up of Silicon Steel Aluminum Iron Steel 34 / 50 The speed of a synchronous motor decreases as the load decreases none of the above increases as the load increases always remain constant 35 / 50 For which motors DOL starter can be used Up to 10 H.P Up to 15 H.P Up to 5 H.P Up to 20 H.P 36 / 50 The filament of electric bulb is made of carbon aluminum tungsten nickel 37 / 50 Currently ISO 9001 is going through which revision cycle 2014 2015 2000 2012 38 / 50 Sulphur hexafluoride is a conductor semiconductor inactive gas dielectric 39 / 50 Which of the following does not change in an ordinary transformer Frequency Current Voltage all of the above 40 / 50 The fuse rating is expressed in terms of kVA VAR current voltage 41 / 50 What is the insulation breakdown voltage of a cable 1000V 1100V 880V 1200V 42 / 50 A 3-phase induction motor runs at 1500rpm at no load and 750rpm at full load when connected to 60Hz 3 phase line. Calculate the number of poles the motor has 4 2 5 8 43 / 50 Transmission line insulators are made of glass P.V.C porcelain iron 44 / 50 Earth wire or ground wire is made up of Al Copper Galvanized steel Iron 45 / 50 H.R.C fuses provide best protection against short circuits overload reverse current open circuits 46 / 50 Power factor of the following circuit will be unity inductance both (a) and (b) capacitance resistance 47 / 50 A fuse is connected none of the above in series with the circuit either in series or parallel with the circuit in parallel with the circuit 48 / 50 Capacitors for power factor correction are rated in kVA kW kV kVAR 49 / 50 What will happen if DC motor is used without starter It will start smoothly Heavy sparking at brushes Depends on load Will not start at all 50 / 50 If the 4 bulbs having power ratings 5W,10W,25W,35W which one will have highest resistance 5W 35W 10W 25W Your score isThe average score is 66% 0% Restart quiz
