STED COUNCIL ELECTRICAL QA\QC 2022 SCHEME 0% STED COUNCIL (QA/QC) Online Exam Your NameEmail-idPhone Number 1 / 50 A fuse is connected either in series or parallel with the circuit none of the above in series with the circuit in parallel with the circuit 2 / 50 Transformer ratings are given in kVA HP kVAR KW 3 / 50 The frequency of domestic power supply in India is 50 Hz 200 Hz 60 Hz 100 Hz 4 / 50 Laminated core in electrical machines are used to reduce copper loss all of the above hysteresis loss eddy current loss 5 / 50 Which type of wiring system is suitable for multistorey building distribution board system Tree system looping out with junction box Ring main system 6 / 50 The material commonly used for sheath of underground cables is Rubber Iron Copper Lead 7 / 50 The field coils of D.C generator are made of carbon copper mica cast iron 8 / 50 What is the standard size of GI earth wire in domestic installation 14 SWG 12 SWG 8 SWG 10 SWG 9 / 50 The medium employed for extinction of arc in air circuit breaker is oil air SF6 vacuum 10 / 50 What is the insulation breakdown voltage of a cable 1000V 1200V 1100V 880V 11 / 50 For which motors DOL starter can be used Up to 10 H.P Up to 5 H.P Up to 15 H.P Up to 20 H.P 12 / 50 Relation between phase voltage and line voltage in three phase delta connected system Vline= Vphase/1.73 Vline= Vphase Vline= 1.73Vphase Vline= 1.41Vphase test wrong answer test right answer 13 / 50 The voltage of the single-phase supply to residential consumer is 210V 230V 110V 400V 14 / 50 In a cable immediately above, metallic sheath _______ is provided armouring none of the above bedding earthing connection 15 / 50 A series motor is best suited for driving none of the above cranes and hoists shear and punches machine tools 16 / 50 Which of the following does not change in an ordinary transformer Voltage all of the above Frequency Current 17 / 50 The filament of electric bulb is made of carbon aluminum nickel tungsten 18 / 50 The insulating material of a cable should have high dielectric strength low-cost all of the above high mechanical strength 19 / 50 Power factor of the following circuit will be unity inductance capacitance both (a) and (b) resistance 20 / 50 Transmission line insulators are made of porcelain iron glass P.V.C 21 / 50 Capacitors for power factor correction are rated in kW kV kVAR kVA 22 / 50 Which of the following circuit element stores energy in the electromagnetic field condenser inductance resistance variable resistor 23 / 50 In which of the following motors the stator and rotor magnetic field rotate at the same speed reluctance motor synchronous motor induction motor universal motor 24 / 50 A 3-phase 4-wire system is commonly used on Primary distribution Secondary distribution Secondary transmission Primary transmission 25 / 50 H.R.C fuses provide best protection against overload reverse current short circuits open circuits 26 / 50 Factors on which soil resistance depends all of the above moisture depth of electrode salt 27 / 50 The operating voltage of high-tension cables is up to 11kV 6.6kV 66kV 33kV 28 / 50 The conductors of the overhead lines are Both (a) and (b) Solid Stranded None of the above 29 / 50 The fuse rating is expressed in terms of kVA VAR current voltage 30 / 50 Sulphur hexafluoride is a inactive gas conductor semiconductor dielectric 31 / 50 The speed of a synchronous motor none of the above always remain constant increases as the load increases decreases as the load decreases 32 / 50 Overhead system can be designed for operation up to 400kV 11kV 66kV 33kV 33 / 50 Distribution lines in India generally use R.C.C poles Steel towers None of the above Wooden poles 34 / 50 The operating voltage of extra high-tension cables is up to 6.6kV 11kV 66kV 33kV 35 / 50 The chemical used in breather for transformer should have the quality of absorbing moisture cooling the transformer oil cleansing the transformer oil ionizing air 36 / 50 Breaking capacity of a circuit breaker is usually expressed in terms of MW MVA volts amperes 37 / 50 3-point starter is used to start the compound motor Both (b) and (c) series motor shunt motor 38 / 50 In an induction motor, rotor slots are usually not quite parallel to the shaft but are given a slight skew Both (a) and (b) To increase the speed of the rotor To reduce the locking tendency of the rotor To reduce the magnetic hum 39 / 50 Differential relays use the principle of Current magnitude comparison between incoming and outgoing feeder Time domain comparison Frequency domain analysis 40 / 50 The algebraic sum of voltages around any closed path in a network is equal to 1 0 negative polarity infinity 41 / 50 Fuse protection is used for current ratings up to 50A 100A 20A 10A 42 / 50 For 66Kv lines the number of insulator disc are used 8 10 6 2 43 / 50 Form factor for a sine wave is 0.637 1.414 1.11 0.707 44 / 50 Permissible current density of GI These motors are not self-starting Back emf of these motors is initially zero These motors have high starting torque To restrict armature current as there is no back emf while starting test wrong answer test right answer 45 / 50 Moisture content in the soil _______ earth soil resistance does not affect decrease none of the above increase 46 / 50 Pin type insulators are not used for voltages beyond 33kV 1kV 22kV 11kV 47 / 50 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 48 / 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 12V 1200V 12000V 49 / 50 Starters are used with D.C motors because Back emf of these motors is initially zero These motors are not self-starting These motors have high starting torque To restrict armature current as there is no back emf while starting test wrong answer test right answer 50 / 50 How much current is produced by a voltage of 18kV across a 15-kilo ohm resistance? 120mA 12mA 12A 1.2A Your score is 0%
