HomePractice MCQ for AE /JE examPractice MCQ machine+p.s Practice MCQ machine+p.s Education April 05, 2023 0 1➤ The commonly used material of condenser tube is Admiralty brassMild steelCast ironAluminium2➤ In an induction motor what is the ratio of rotor copper- loss and rotor input (A) (B) (C) (D) S/(1-S)S1/S(1-S)3➤ The pressure at the furnace is minimum in case of Natural draught systemInduced draught system Balanced draught systemForce draught system4➤ What are the conditions to be satisfied for alternators to be synchronized with an incoming supply? 1. Equal voltage 2. Equal frequency 3. Same power rating 4. Same phase sequence Select the correct answers using the code given below 1, 2 and 43 and 42, 3 and 41, 2 and 35➤ How can reactive power delivered by a synchronous generator be controlled? By hanging the prime moves speedBy changing the direction of rotationBy changing the prime moves inputBy changing the excitation6➤ In hard-tool applications which one of the following single-phase motors is used?Capacitor run motorAC series motorCapacitor start motorShaded pole motor7➤ What is the angle between the induced voltage and supply voltage of a synchronous motor under running generation? Between 90° and 180° >180Greater than zero but =< 90°Zero8➤ When does a synchronous motor operate with leading power factor current? While it is heavily loadedWhile it is over excitedWhile it is critically excited While it is under excited9➤ The crawling in the induction motor Is caused by Harmonics developed in motorHigh loadsLow voltage supplyImproper design of stator lamination10➤ Which of the following motors is most suitable for signaling devices and many kinds of timers Inductance motord.c series motorReluctance motord.c shunt motor11➤ According to Fleming’s right hand rule for finding the direction induced emf, when induced finger points in the direction of induced emf, forefinger will point the direction of Motion of conductorLines of forceEither of the aboveNone of the above12➤ Reheat factors in steam turbine depends onInitial pressure and temperature onlyExit pressure onlyStage efficiency onlyAll of these13➤ For the same maximum demand if load factors are decreased, the cost of generation will IncreaseDecreaseRemain unchangedNone of these14➤ Bundle conductors in a transmission line None of theseNo effectIncreases radio interferenceReduce radio interference15➤ For cooling of large size generators hydrogen is used because All of theseIt has high thermal conductivity It offers reduced fire riskIt is light 16➤ A negative sequence relay is commonly used to protect A transmission lineA bus bar A transformerAn alternator17➤ Which part of a motor needs maximum attention for maintenance Stator windingRotor windingBearingFrame18➤ Which of the following is the advantages of electric breaking (A) (B) (C) (D) More heat is generated during breakingIt avoids wear of track It is instantaneousAll of the above 19➤ The dc series motors are preferred for traction applications because Torque and speed are inversely proportional to armature currenThe torque is proportional to square of armature Current and the speed is inversely proportional to the torqueThe torque is proportional to the square root of armature currentThe torque is proportional armature current20➤ Sparking at the commutators of a dc motor may result inIncreased power consumptionDamage to the commutator’s insulationDamage to the commutator’s segmentsAll of the above21➤ The flash point of transformers oil should be higher than 104°C80°C60°C40°C22➤ A large value of short-circuit indicator A poor power factorZero power factorA good power factorNone of the above23➤ Which type of connection is employed for current transformers for the protection of star-delta connected 3-phase transformer star-delta delta-starstar-stardelta-delta24➤ Francis turbine is usually used for For all headsHigh installation above 180mLow head installation up to 30mMedium head installation from 30m to 180m25➤ Which of the following is not a source of power? ThermocouplePhoto electric cellPhotovoltaic cell Solar cell SubmitYour score is Tags Practice MCQ for AE /JE exam Newer Older