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