0% 0 Electrical Engineering Quiz 3 1 / 50 During reverse recovery time__________________? charge carrier of junction J1 is swept out charge carrier of junction J3 is swept out charge carrier of junction J2 recombined both B and C 2 / 50 Automatic signalling is used for which of the following trains ? Superfast trains Suburban and Urban electric trains Mail and express trains All trains 3 / 50 The value of VBE ___________________? Is almost independent of IC None of the above Depends upon IC to moderate extent Is strongly dependant on IC 4 / 50 A forward biased pn junction diode has a resistance of the order of_____________? MO None of the above O kO 5 / 50 The starting torque in case of centrifugal pumps is generally_________________? same as running torque double the running torque less than running torque slightly more than running torque 6 / 50 Copper oxide rectifier is usually designed not to operate above___________? 30?C 10?C 20?C 45?C 7 / 50 A feeder, in a transmission system, feeds power to________________? distributors service mains all of the above generating stations 8 / 50 The thickness of metallic shielding on cables is usually_______________? 0.04 mm None 0.2 to 0.4 mm 40 to 60 mm 9 / 50 In Thevenin?s theorem, to find Z all independent voltage and current sources are short circuited all independent current sources are short circuited and independent voltage sources are open circuited all independent voltage sources are short circuited and all independent current sources are open circuited all independent voltage sources are open circuited and all independent current sources are short circuited 10 / 50 Following will happen if the specific gravity of electrolyte becomes more than 1.23 Corrosion of the grids of the plate Loss of life Loss of capacity All above 11 / 50 In superhetrodyne receiver, the input at mixer stage is________________? IF and AF RF and AF IF and RF RF and local oscillator signal 12 / 50 Primary air is that air which is used to_____________? transport and dry the coal provide air around burners for get?ting optimum combustion reduce the flame length increase the flame length 13 / 50 A voltmeter should have ____________resistance? None of the above Zero Very high Very low 14 / 50 If free space between the plates of a capacitor is replaced by a dielectric_____________? The potential difference remains constant capacittance decreases and energy increases both potential difference and capacitance decrease but energy increases The potential difference decreases but both capacitance and energy increase The potential difference remains constant capacittance and energy stored increases 15 / 50 The purpose of capacitors in a transistor amplifier is to___________________? Provide biasing Protect the transistor Couple or bypass a.c. component Cool the transistor 16 / 50 Admittance relay is __________ relay? directional impedance non-directional none of the above 17 / 50 In three-phase squirrel-cage induction motors____________? rotor conductors are short-circuited through end rings rotor conductor ends are short-circuited through slip rings rotor conductors are connected to insulation rotor conductors are kept open 18 / 50 An induction motor is identical to_________? synchronous motor D.C. compound motor D.C. series motor asynchronous motor 19 / 50 For the safety of a steam boiler the number of safety valves fitted are____________? three four two one 20 / 50 The cost of an induction motor will increase as________________? horsepower rating increases but r.p.m. decreases horsepower rating and operating speed decreases horsepower rating and operating speed increases horsepower rating decreases but r.p.m. increases 21 / 50 Annual depreciation cost is calculated by___________? none of the above All sinking fund method straight line method 22 / 50 Which of the following primary cells has the lowest voltage_________ ? Carbon-zinc Zinc-chloride Mercury Lithium 23 / 50 The maximum efficiency of transformer coupled class A power amplifier is _______________? 80% 45% 50% 30% 24 / 50 Annual depreciation as per straight line method, is calculated by__________? the capital cost minus the salvage value, is divided by the number of years of life increasing a uniform sum of money per annum at stipulated rate of interest none of the above the capital cost divided by number of year of life 25 / 50 The alternating current has frequency of 106 Hz in such a way that time period for completion of cycle is_______________? 1sec 1.5Hzs 106sec 1Hzs 26 / 50 In a three-phase mercury arc rectifiers each anode conducts for____________? one-third of a cycle one-fourth of a cycle two-third of a cycle one-half a cycle 27 / 50 The direction of electric field due +0 positive charge is ___________? All away from the charge none of the above towards the charge 28 / 50 The voltage gain in a transistor connected in___________arrangement is the highest? common collector common emitter none of the above common base 29 / 50 When secondary of a current transformer is open-circuited its iron core will be__________? hot because primary will carry heavy current none of above will happen cool as there is no secondary current hot because of heavy iron losses taking place in it due to high flux density 30 / 50 The efficiency of a machine should be as ____________ as possible to reduce the operating cost? either of the above high none of the above low 31 / 50 If the supply frequency to the transformer is increased,?the iron loss will__________? any of the above decrease not change increase 32 / 50 The armature of D.C. generator is laminated to_______________? reduce the bulk provide the bulk insulate the core reduce eddy current loss 33 / 50 With the increase in temperature, the speed of DC shunt motor____________? remain same increases decreases. none of the above 34 / 50 In a boiler installation the natural draught is produced_____________? due to the fact that pressure at the grate due to cold column is higher than the pressure at the chimney base due to hot column all of the above due to the fact that furnace gases being light go through the chimney giving place to cold air from outside to rush in due to the fact that at the chimney top the pressure is more than its environmental pressure 35 / 50 Which instrument is used to measure the power of electric circuit ? None of these Wattmeter Viscometer Wavemeter 36 / 50 By which of the following methods the temperature rise of windings and other parts may be determined ? Any of the above Thermometer method Resistance method Embedded temperature detector method 37 / 50 Load factor of a power station is defined as____________? none of the above average load/maximum demand average load x maximum demand maximum demand/average load 38 / 50 A crystal diode utilises ?????.. characteristic for rectification reverse none of the above forward or reverse forward 39 / 50 The force between two long parallel conductors is inversely proportional to_____________? product of current in two conductors radius of conductors distance between the conductors current in one conductor 40 / 50 The substances which combine together to store electrical energy during the charge are called ________ materials active passive inert dielectric 41 / 50 At parallel resonance, the net reactive component circuit current is _______________? Zero None of the above Capacitive Inductive 42 / 50 Static capacitors are rated in terms of_____________? kW none of the above kWh kVAR 43 / 50 Which of the following problem arises in D.C. motors which are fed from thyristor bridge circuits ? Increased I R losses Increased core losses All of the above Poor commutation 44 / 50 In case of a steam engine an average coal consumption per km is nearly________________? 28 to 30 kg 60 to 80 kg 100 to 120 kg 150 to 175 kg 45 / 50 Power amplifiers handle ______________ signals compare to voltage amplifiers? Large None of the above Small Very small 46 / 50 The ratio of reverse resistance and forward resistance of a germanium crystal diode is about ______________? 100:01:00 1:01 1000:01:00 40,000 : 1 47 / 50 One maxwell is equal to____________? 10 webers 10 webers 10 webers 10 webers 48 / 50 A single phase one pulse controlled circuit has a resistance R and counter emf E load 400 sin(314 t) as the source voltage. For a load counter emf of 200 V, the range of firing angle control is _____? 60? to 120?. 60? to 180?. 30? to 180?. 30? to 150?. 49 / 50 An amplifier receives 0.1 W of input signal and delivers 15 W of signal power. What is the power gain in db? 8 db 4 db 6 db 5 db 50 / 50 Maximum demand on a power plant is_________________? instantaneous maximum value of kVA supplied during a period the greatest of all ?short time interval averaged? demand during a period All none of the above Provide Your Information Your score is The average score is 0% LinkedIn Facebook Twitter 0% Restart quiz Send feedback Share on facebook Facebook Share on twitter Twitter Share on whatsapp WhatsApp PrevElectrical Engineering Quiz 2 Electrical Engineering Quiz 4Next
