0% 0 Electrical Engineering Quiz 7 1 / 50 If a shunt motor is started with its field winding open then___________? None of these It will rotate at dangerously high speed It will rotate at less speed as that with its field winding closed It will rotate at the same speed as that with its field winding closed 2 / 50 If a self excited D.C. generator after being installed, fails to build up on its first trial run, the first thing to do is to______________? increase the field resistance increase the speed of primemover check armature insulation resistance reverse the field connections 3 / 50 In the cables, the location of fault is usually found out by comparing____________? all above parameters the capacitances of insulated conductors the inductance of conductors the resistance of the conductor 4 / 50 In a crystal, an atom vibrates at a frequency determined by_______________? the stiffness of the bonds it makes with neighbors the heat content of the crystal the temperature of the crystal None 5 / 50 An IC has _______________size? Extremely small Large None of the above Very large 6 / 50 The main source of production of biogas is__________________? all above wet cow dung human waste wet livestock waste 7 / 50 A Zener diode is used as a _____________voltage regulating device? Shunt None of the above Series-shunt Series 8 / 50 The active materials on the positive and negative plates of a fully charged lead-acid battery are_______? none of the above lead sulphate and lead lead peroxide and lead lead and lead peroxide 9 / 50 The doping level in a zener diode is______________ that of a crystal diode? the same as less than more than none of the above 10 / 50 Pressure cables are generally not used beyond__________? 11 kV 66 kV 132 kV 33 kV 11 / 50 Charging a sulphated battery at high rate results in___________? damage to separators, cell caps covers and battery case due to excessive temperature warping of plates boiling of electrolyte due to gassing all above 12 / 50 DIAC and TRIAC both are semiconductors devices and conduct in____________________? DIAC conducts in forward direction and TRIAC conducts in reverse direction Both conducts in forward direction Both conducts in reverse direction Both conducts in either direction 13 / 50 In a mercury arc rectifier________ flow from anode to cathode ions electrons ions and electrons any of the above 14 / 50 The thickness of the layer of insulation on the conductor, in cables, depends upon___________? current carrying capacity power factor reactive power voltage 15 / 50 Thermocouples are mainly used for the measurement of_____________? temperature resistance eddy currents coupling co-efficient 16 / 50 Armature reaction of an unsaturated D.C. machine is_____________? demagnetising none of above crossmagnetising magnetising 17 / 50 On which of the following effects of electric current a fuse operates ? Heating effect Electrostatic effect Magnetic effect Photoelectric effect 18 / 50 D.C. servomotors are used in______________? both D.C. and A control systems none of the above purely D.C. control systems 19 / 50 Brushes of D.C. machines are made of_________? hard copper soft copper carbon all of above 20 / 50 For an Op-amp with negative feedback, the output is_________________? fed back to the inverting input fed back to the noninverting input equal to the input increased 21 / 50 60 thyrsistors are connected in series and parallel to form a 10 KV and 5.5 KA switch. Each thyristor is rated for 1.2 KV, 1 K The no. of parallel path are 6. The efficiency of the switch is______________________? 90.90% 83.30% 91.60% 76.30% 22 / 50 ________________ motor is a constant speed motor? Synchronous motor Schrage motor Induction motor Universal motor 23 / 50 The electrostatic stress in underground cables is_________? maximum at the conductor and minimum at the sheath zero at the conductor as well as on the sheath same at the conductor and the sheath minimum at the conductor and maximum at the sheath 24 / 50 For frequencies above the resonant frequency, a parallel LC circuit behaves as a ____________ load? Resistive Capacitive None of the above Inductive 25 / 50 In induction heating ___________ is abnormally high? phase angle voltage frequency current 26 / 50 Air-core coils are practically free from______________? both (A) and (B) eddy current losses none of the above hysteresis losses 27 / 50 A negative clipper removes the ______________half-cycles of the input voltage? Both positive and negative Negative Positive None of the above 28 / 50 To measure and voltage by using an A.C. potentiometer, it is desirable that the supply for the potentiometer in taken_______________? from a source which is not the same as the unknown voltage any of the above from the same source as the unknown voltage from a battery 29 / 50 is that property of a capacitor which delays any change of voltage across it ? Potential gradient Capacitance None of the above Inductance 30 / 50 Burden of a protective relay is the power______________? developed by the relay circuit required to operate the circuit breaker none of the above absorbed by the circuit of relay 31 / 50 For power output higher than 15 kW, the suitable rectifier is________________? 3 phase Poly phase Single phase Only (b) and (c) 32 / 50 In a synchronous motor, the magnitude of stator back e.m.f. Eb depends on___________? both the speed and rotor flux none of the above load on the motor d.c. excitation only 33 / 50 Aluminium when adopted as a conductor material in __________ transformers, decreases the overall cost of the transformer? large size any of the above size medium size small size 34 / 50 The power factor at resonance in R-L- C parallel circuit is________? 0.08 lagging zero unity 0.8 leading 35 / 50 In a power plant if the maximum demand on the plant is equal to the plant capacity, then plant reserve capacity will be zero load factor will be unity diversity factor will be unity load factor will be nearly 60% 36 / 50 The heat dissipating capability of transformers of ratings higher than 30 kVA in increased by providing which of the following ? Fins All of the above Tubes Corrugations 37 / 50 An ohmmeter is a____________? dynamometer instrument none of the above moving iron instrument moving coil instrument 38 / 50 Practical way of obtaining static voltage equalization in series connected SCRs is by the use of____________? Resistors of different values across each SCR One resistor across the string Resistors of the same value across each SCR One resistor in series with each SCR 39 / 50 Resistance of a material always decreases if___________? number of free electrons available become more temperature of material is increased none of the above is correct temperature of material is decreased 40 / 50 The positive clipper is that which removes the ____________half-cycles of the input voltage? Both positive and negative None of the above Positive Negative 41 / 50 If R2 is the resistance of secondary winding of the transformer and K is the transformation ratio then the equivalent secondary resistance referred to primary will be___________? R2/VK R22/K R2IK2 R22!K2 42 / 50 Varistors are______________? non-linear resistors carbon resistors resistors with zero temperature coefficient insulators 43 / 50 Two generators are running in parallel. One of the generators may run as motor for which of the following reasons ? The direction of that generator is reversed That generator takes large share of loads The field of that generator is weakened The speed of that generator is increased 44 / 50 When two D.C. series motors are connected in parallel, the resultant speed is____________? normal speed more than the normal speed loss than the normal speed zero 45 / 50 A shaded pole motor does not possess___________? all of the above centrifugal switch commutator capacitor 46 / 50 The resistance of armature winding depends on length of conductor number of conductors all of the above cross-sectional area of the conductor 47 / 50 Non-linear resistors______________? follows Ohm?s law at low temperatures only result in non-uniform heating produce harmonic distortion none of the above 48 / 50 Which of the following generating station has minimum running cost ? Thermal Hydro Diesel Nuclear 49 / 50 For heating element high resistivity material is chosen to______________? reduce the length of heating element produce large amount of heat increase the life of the heating element reduce the effect of oxidation 50 / 50 Transistor biasing is generally provided by a_______________? Diode Biasing circuit None of the above Bias battery 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 6 Electrical Engineering Quiz 8Next
