0% 1 Electrical Engineering Quiz 1 1 / 50 The core used in high frequency transformer is usually___________? copper core air core mild steel core cost iron core 2 / 50 Which of the following is the disadvantage of electric traction over other systems of traction ? Corrosion problems in the under-ground pipe work All of the above Short time power failure interrupts traffic for hours High capital outlay in fixed installations beside route limitation 3 / 50 Wave trap is used to trap waves of__________________? either of the above higher frequencies entering generator or transformer units none of the above power frequencies 4 / 50 In a phase-shift control method, the phase shift between anode and grid voltages can be achieved by means of______________? shunt motor synchronous generator induction regulator synchronous motor 5 / 50 N/C =_____________? A/m V/A V/m J/V 6 / 50 International ohm is defined in terms of the resistance of________________? a cube of carbon a column of mercury the unit length of wire a cube of copper 7 / 50 The value of ? for a transistor is generally____________? above 500 less than 1 1 between 20 and 500 8 / 50 Regenerative cycle thermal efficiency_______________? is always greater than simple Rankine thermal efficiency is greater than simple Rankine cycle thermal efficiency only when steam is bled at particular pressure is always less than simple Rankine cycle thermal efficiency is same as simple Rankine cycle thermal efficiency 9 / 50 A capacitor having capacitance of 5 uF is charged to a potential difference of 10,000 V. The energy stored in the capacitor is__________? 250 joules 150 joules 200 joules 50 joules 10 / 50 In a parallel LC circuit, if the input signal frequency is increased above resonant frequency then _______________? XL increases and XC decreases Both XL and XC increase XL decreases and XC increases Both XL and XC decrease 11 / 50 Number of PN junction in an SCR is____________? Three Five Two Four 12 / 50 A closed switch has a resistance of_____________? infinity about 50 ohms zero about 500 ohms 13 / 50 There is a greater possibility of occurence of corona during______________? winter summer heat humid weather dry weather 14 / 50 Maximum power loss occurs during_________________? spread time all rise time delay time 15 / 50 Approximate estimation of power demand can be made by_____________? all of the above statistical methods mathematical method load survey method 16 / 50 The first order control system, which is well designed, has a_______________? none of the above small bandwidth negative time constant large negative transfer function pole 17 / 50 The ratio of exit pressure to inlet pressure of maximum mass flow rate per area of steam through a nozzle when steam is initially superheated is__________? 0.5457 0.555 0.578 0.6 18 / 50 If/, R and t are the current, resistance and time respectively, then according to Joule?s law heat produced will be proportional to_______________? I2Rf I2R2t* I2R2t I2Rt 19 / 50 A light bulb draws 300 mA when the voltage across it is 240 V. The resistance of the light bulb is___________? 600 Q 400 Q 1000 Q 800 Q 20 / 50 A _________ is used to measure the stator % winding temperature of the generator? pyrometer thermocouple thermometer resistance thermometer 21 / 50 A series ohmmeter circuit uses a 3 V battery and a 1 mA meter movement. What is the half-scale resistance for this movement ? 6 kO kO 3 kO kO 22 / 50 During the idle period of the battery, strong electrolyte tends to change the active material of the cell into____________? PbSC-4 Pb02 PbO Pb 23 / 50 Harmonics in 3 phase inverters can be reduced by using___________? Active filter Both passive and active filters None of these Passive filter 24 / 50 Temperature co-efficient of resistance is expressed in terms of___________? ohms/?C ohms/ohm?C mhos/?C mhos/ohm?C 25 / 50 The units of capacitance are____________? coulombs/volt henry/Wb ohms volts/coulomb 26 / 50 The most costly coupling is _______________ coupling? Transformer Direct RC Impedance 27 / 50 To achieve sparkless commutation brushes of a D.C. generator are rockedm ahead so as to bring them? just ahead of magnetic neutral axis in magnetic neutral axis just behind the magnetic neutral axis none 28 / 50 In a transformer the resistance between its primary and secondary should be_____________? zero 1000 Q 10 Q infinity 29 / 50 At the base-emitter junctions of a transistor, one finds___________? low resistance none of the above a wide depletion layer a reverse bias 30 / 50 Which of the following is the disadvantage of a synchronous condenser? All of the above Noise Continuous losses in motor High maintenance cost 31 / 50 The PIV rating of each diode in a bridge rectifier is ___________that of the equivalent center-tap rectifier? four times the same as one-half twice 32 / 50 In case of a 4-pole D.C. generator provided with a two layer lap winding with sixteen coils, the pole pitch will be__________________? 32 4 8 16 33 / 50 Which of the following rectifiers are primarily used for charging of low voltage batteries from AC supply ? Mechanical rectifiers Electrolytic rectifiers Selenium rectifiers Copper oxide rectifiers 34 / 50 An SCR combines the features of ____________? A rectifier and capacitor A rectifier and resistance None of the above A rectifier and transistor 35 / 50 Due to which of the following factors the brush wear rate is altered ? Surface conditions of brush and commutator Speed of the machine Contact pressure All of the above 36 / 50 A rectifier with an external low pass filter is an example of______________? Direct switch matrix circuits All of these Indirect switch matrix circuits Embedded converters 37 / 50 Oil switches are employed for_____________? low currents circuits low voltages circuits all circuits high voltages and large currents circuits 38 / 50 Direct conversion of heat into electrical energy is possible through____________? fuel cells solar cells MHD generators none of the above 39 / 50 The hot resistance of the bulb?s filament is higher than its cold resistance because the temperature co-efficient of the filament is___________________? about 2 ohms per degree negative zero positive 40 / 50 Three capacitors each of the capacity C are given. The resultant capacity 2/3 C can be obtained by using them_____________? two in series and third in parallel across this combination two in parallel and third in series with this combination all in series all in parallel 41 / 50 In medium sized induction motors, the slip is generally around___________? 4% 0.04% 14% 0.40% 42 / 50 Power transistor are type of___________? MOSFETs IGBTs All of above B.JTs 43 / 50 Belted slip ring induction motor is almost invariably used for_________________? jaw crushers none of the above water pumps centrifugal blowers 44 / 50 A synchronous motor can be made self starting by providing? none of the above damper winding on rotor poles damper winding on stator as well as rotor poles damper winding on stator 45 / 50 ?The surface integral of the normal component of the electric displacement D over any closed surface equals the charge enclosed by the surface?. The above statement is associated with_______? Lenz?s law Faraday?s law Gauss?s law Kirchhoff s law 46 / 50 For cost and safety, the outdoor substations are installed for voltages above_________________? 11 kV 33 kV 110kV 60kV 47 / 50 Which of the following motors is inherently self starting ? Shaded-pole motor Reluctance motor None of these Split motor 48 / 50 The efficiency of diesel locomotives is nearly_______________? 60 to 70 percent 45 to 55 percent 20 to 25 percent 30 to 40 percent 49 / 50 In a glass bulb mercury arc rectifier the maximum current rating is restricted to___________? 1500 A 500 A 2000 A 1000 A 50 / 50 A charge of 0.10C accelerated through a potential difference of 1000V acquires kinetic energy_______________? 200J 100 eV 1000J 100J Provide Your Information Your score is The average score is 54% LinkedIn Facebook Twitter 0% Restart quiz Send feedback Share on facebook Facebook Share on twitter Twitter Share on whatsapp WhatsApp Electrical Engineering Quiz 2Next
