STED COUNCIL ELECTRICAL QA\QC 2022 SCHEME 0% STED COUNCIL (QA/QC) Online Exam Your NameEmail-idPhone Number 1 / 50 1) A 3-phase 4-wire system is commonly used on Secondary transmission Secondary distribution Primary transmission Primary distribution 2 / 50 2) H.R.C fuses provide best protection against overload open circuits reverse current short circuits 3 / 50 3) How much current is produced by a voltage of 18kV across a 15-kilo ohm resistance? 120mA 12mA 1.2A 12A 4 / 50 4) The speed of a synchronous motor increases as the load increases none of the above always remain constant decreases as the load decreases 5 / 50 5) Overhead system can be designed for operation up to 11kV 400kV 66kV 33kV 6 / 50 6) A fuse is connected in parallel with the circuit none of the above in series with the circuit either in series or parallel with the circuit 7 / 50 7) A series motor is best suited for driving shear and punches cranes and hoists machine tools none of the above 8 / 50 8) The fuse rating is expressed in terms of kVA voltage VAR current 9 / 50 9) Form factor for a sine wave is 1.11 1.414 0.707 0.637 10 / 50 10) The operating voltage of extra high-tension cables is up to 11kV 33kV 6.6kV 66kV 11 / 50 11) What will happen if DC motor is used without starter Will not start at all It will start smoothly Depends on load Heavy sparking at brushes 12 / 50 12) The frequency of domestic power supply in India is 50 Hz 200 Hz 100 Hz 60 Hz 13 / 50 13) The voltage of the single-phase supply to residential consumer is 230V 210V 110V 400V 14 / 50 14) For 66Kv lines the number of insulator disc are used 10 8 6 2 15 / 50 15) The medium employed for extinction of arc in air circuit breaker is vacuum air oil SF6 16 / 50 16) Capacitors for power factor correction are rated in kV kW kVAR kVA 17 / 50 17) Laminated core in electrical machines are used to reduce eddy current loss hysteresis loss all of the above copper loss 18 / 50 18) Which type of wiring system is suitable for multistorey building Tree system looping out with junction box distribution board system Ring main system 19 / 50 19) In which of the following motors the stator and rotor magnetic field rotate at the same speed universal motor reluctance motor induction motor synchronous motor 20 / 50 20) The chemical used in breather for transformer should have the quality of cooling the transformer oil cleansing the transformer oil absorbing moisture ionizing air 21 / 50 21) For which motors DOL starter can be used Up to 15 H.P Up to 5 H.P Up to 10 H.P Up to 20 H.P 22 / 50 22) The filament of electric bulb is made of aluminum nickel tungsten carbon 23 / 50 23) Pin type insulators are not used for voltages beyond 33kV 22kV 1kV 11kV 24 / 50 24) Relation between phase voltage and line voltage in three phase delta connected system Vline= Vphase/1.73 Vline= 1.73Vphase Vline= 1.41Vphase Vline= Vphase test wrong answer test right answer 25 / 50 25) Permissible current density of GI These motors have high starting torque These motors are not self-starting To restrict armature current as there is no back emf while starting Back emf of these motors is initially zero test wrong answer test right answer 26 / 50 26) The field coils of D.C generator are made of copper mica carbon cast iron 27 / 50 27) What is the insulation breakdown voltage of a cable 1000V 880V 1100V 1200V 28 / 50 28) The operating voltage of high-tension cables is up to 6.6kV 11kV 66kV 33kV 29 / 50 29) The conductors of the overhead lines are Stranded Both (a) and (b) None of the above Solid 30 / 50 30) Which of the following does not change in an ordinary transformer Frequency Voltage all of the above Current 31 / 50 31) Differential relays use the principle of Time domain comparison Frequency domain analysis Current magnitude comparison between incoming and outgoing feeder 32 / 50 32) What is the standard size of GI earth wire in domestic installation 14 SWG 12 SWG 8 SWG 10 SWG 33 / 50 33) In an induction motor, rotor slots are usually not quite parallel to the shaft but are given a slight skew To reduce the locking tendency of the rotor Both (a) and (b) To increase the speed of the rotor To reduce the magnetic hum 34 / 50 34) Transmission line insulators are made of P.V.C glass iron porcelain 35 / 50 35) In a cable immediately above, metallic sheath _______ is provided bedding armouring earthing connection none of the above 36 / 50 36) Factors on which soil resistance depends all of the above salt depth of electrode moisture 37 / 50 37) 3-point starter is used to start the compound motor Both (b) and (c) shunt motor series motor 38 / 50 38) Breaking capacity of a circuit breaker is usually expressed in terms of volts amperes MVA MW 39 / 50 39) Which of the following circuit element stores energy in the electromagnetic field variable resistor inductance condenser resistance 40 / 50 40) Transformer ratings are given in kVAR kVA HP KW 41 / 50 41) Starters are used with D.C motors because To restrict armature current as there is no back emf while starting These motors have high starting torque These motors are not self-starting Back emf of these motors is initially zero test wrong answer test right answer 42 / 50 42) Distribution lines in India generally use None of the above Wooden poles R.C.C poles Steel towers 43 / 50 43) Moisture content in the soil _______ earth soil resistance decrease increase does not affect none of the above 44 / 50 44) The primary winding of a transformer has a 120V ac supply. What is the value of secondary voltage if the turns ratio is 10 12V 12000V 1200V 120V 45 / 50 45) Sulphur hexafluoride is a semiconductor inactive gas dielectric conductor 46 / 50 46) Fuse protection is used for current ratings up to 20A 100A 50A 10A 47 / 50 47) The algebraic sum of voltages around any closed path in a network is equal to infinity 0 1 negative polarity 48 / 50 48) Power factor of the following circuit will be unity both (a) and (b) resistance inductance capacitance 49 / 50 49) The material commonly used for sheath of underground cables is Copper Lead Iron Rubber 50 / 50 50) The insulating material of a cable should have high mechanical strength high dielectric strength all of the above low-cost Your score is 0%
