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