0% 0 Electrical Engineering Quiz 6 1 / 50 In case of _________________ free running and coasting periods are generally long ? all of the above main-line service urban service sub-urban service 2 / 50 For a D.C. shunt motor if the excitation is changed_______________? torque, power and speed, all will change torque will change but power will remain constant torque will remain constant torque and power both will change 3 / 50 The ionization potential of mercury is approximately_____________? 8.4 V 5.4 V 16.4 V 10.4 V 4 / 50 Which of the following statements regarding a reluctance motor is incorrect ? It cannot be reversed, ordinarily It requires no D.C. field excitation for its operation It is nothing else but a single-phase, salient pole synchronous-induction motor Its squirrel cage-rotor is of unsym-metrical magnetic construction in order to vary reluctance path between stator and rotor 5 / 50 Phase margin of a system is used to specify which of the following ? Relative stability Time response Absolute stability Frequency response 6 / 50 To avoid the effect of stray magnetic field in A.C. bridges we can use_______________? magnetic screening wave filters Wagner earthing device any of the above 7 / 50 In an LC transistor oscillator, the active device is___________? Transistor LC tank circuit None of the above Biasing circuit 8 / 50 Which of the following methods does not take into account the maximum temperature rise under variable load conditions ? Equivalent current method Equivalent power method Equivalent torque method Method of average losses 9 / 50 In radiative coupling, the emitter radiation field_____________? Decays as 2R, where R is the separation distance between the emitter and the receptor Decays as R, where R is the separation distance between the emitter and the receptor Decays as 1 / R, where R is the separation distance between the emitter and the receptor Decays as 1 / 2 R, where R is the separation distance between the emitter and the receptor 10 / 50 For a consumer the most economical power factor is generally____________? 0.5 leading 0.5 lagging 0.95 leading 0.95 lagging 11 / 50 For measurements on high voltage capacitors, the suitable bridge is_______________? Schering bridge Modified De Santy?s bridge Wein bridge Any of the above 12 / 50 Form factor of a rectifier is the ratio of ______________? Root mean square value of voltage and current to its peak value Peak value of current and voltage to its root mean square value Average value of current and voltage to its root mean square value Root mean square value of voltage and current to its average value 13 / 50 The initial permeability of an iron rod is________________? the permeability almost in non-magnetised state the lowest permeability of the iron rod the permeability at the end of the iron rod the highest permeability of the iron rod 14 / 50 The auto-starters (using three auto transformers) can be used to start cage induction motor of the following type__________? star connected only none of the above All delta connected only 15 / 50 To limit short-circuit current in a power system are used______________? reactors earth wires isolators H.R. fuses 16 / 50 The breakdown of insulation of the cable can be avoided economically by the use of___________? both (A) and (B) insulating materials with different dielectric constants inter-sheaths none of the above 17 / 50 Which of the following power plant has least fuel transportation______________? thermal power plants steam power stations diesel generating plants nuclear power plants 18 / 50 For high value of diversity factor, a power station of given installed capacity will be in a position to supply? less number of consumers All None more number of consumers 19 / 50 In which?of the following power plants the maintenance cost is usually high? Nuclear power plant Thermal power plants Hydro-electric power plants Diesel engine power plants 20 / 50 A repulsion motor is equipped with__________? slip rings All none of the above commutator 21 / 50 A zener diode has ________________? none of the above three pn junctions one pn junction two pn junctions 22 / 50 A pn junction acts as a__________________? None of the above Controlled switch Bidirectional switch Unidirectional switch 23 / 50 With the increase in temperature, the speed of DC series motor______________? decreases increases remain same none of the above 24 / 50 An open coil has_____________? infinite resistance and zero inductance zero resistance and high inductance zero resistance and inductance infinite resistance and normal inductance 25 / 50 Cables, generally used beyond 66 kV are___________? S.L. type belted armoured oil filled 26 / 50 Carbon rods are used in wet and dry cells because_____________? carbon can resist the attack of battery acid carbon rod serves as conductor both (A) and (B) either (A) or (B) 27 / 50 Synchronous motors are generally not self-starting because: startes cannot be used on these machines the direction of rotation is not fixed the direction of instantaneous torque reverses after half cycle starting winding is not provided on the machines 28 / 50 Hopkinson?s test on D.C. machines is conducted at_______________? no-load full-load overload part load 29 / 50 What is the total resistance of a voltmeter on the 10 V range when the meter movement is rated for 50 ?A of full-scale current ? 200 kO None of the above 20 kO 10 kO 30 / 50 The transfer function of PWM is generally developed in______________? All Frequency domain None of these Time domain 31 / 50 While applying Fleming?s right-hand rule to And the direction of induced e.m.f., the thumb points towards___________? direction of motion of the conductor if forefinger points in the direction of generated e.m.f. direction of motion of conductor, if forefinger points along the lines of flux direction of induced e.m.f. direction of flux 32 / 50 In class A operation, the operating point is generally located_____________of the d.c. load line? At the middle At cut off point None of the above At saturation point 33 / 50 The parameter hie stands for input impedance in _____________? CE arrangement with output shorted None of the above CB arrangement with output shorted CC arrangement with output shorted 34 / 50 For closer tolerances which of the following capacitors is usually preferred ? Ceramic disc capacitor None of the above Paper capacitor Mica capacitor 35 / 50 When the demand of consumers is not met by a power plant, it will resort to which of the following? Efficient plant operation Penalising high load consumers by increasing the charges for electricity Power factor improvement at the , generators Load shedding 36 / 50 Most sensitive galvanometer is_____________? spot ballistic galvanometer elastic galvanometer Duddlb galvanometer vibration galvanometer 37 / 50 In ______________ the speed can be varied by changing the position of brushes? slip ring motor induction motor repulsion motor schrage motor 38 / 50 Tractive effort is required to_____________? do all of the above overcome the gravity component of train mass overcome friction, windage and curve resistance accelerate the train mass 39 / 50 In a commutator_____________? none of the above mica is harder than copper mica and copper are equally hard copper is harder than mica 40 / 50 The crawling in the induction motor is caused by____________? high loads harmonics develped in the motor improper design of the machine low voltage supply 41 / 50 When the initial conditions of a system are specified to be zero it implies that the system is______________? at rest but stores energy working normally with reference input working normally with zero reference input at rest without any energy stored in it 42 / 50 Which of the following is an electromagnetically device ? Thermocouple LVDT Any of the above Induction relay 43 / 50 When an iron piece is placed in a magnetic field_____________? the magnetic lines of force will bend away from their usual paths in order to pass through the piece the magnetic lines of force will bend away from their usual paths in order to go away from the piece the iron piece will break the magnetic field will not be affected 44 / 50 Besides a constant speed a synchronous rotor possesses which of the following advantages ? All of the above Lower cost High power factor Better efficiency 45 / 50 You have to replace 1500 Q resistor in radio. You have no 1500 Q resistor but have several 1000 Q ones which you would connect__________? three in series two in parallel two in parallel and one in series three in parallel 46 / 50 For a hole which of the following statements is incorrect ? Holes can exist in any material including conductors Holes may constitute an electric current Holes can be considered as a net positive charge Holes can exist in certain semiconductors only 47 / 50 A transformer oil must be free from________________? sludge moisture odour gases 48 / 50 n a common-source JFET amplifier, the output voltage is _____________? 90o out of phase with the input 180o out of phase with the input taken at the source in phase with the input 49 / 50 The air resistance to the movement of the train is proportional to_____________? speed (speed) (speed) 1/speed 50 / 50 Kingdom Protoctista includes_______________? Eu-cariotiquic organisms Unicellular organisms Prokaryotic organisms Fungi 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 5 Electrical Engineering Quiz 7Next
