Synchronous Generator Question & Answers February 4, 2023 By Wat Electrical This article lists 100 Synchronous Generator MCQs for engineering students. All the Synchronous Generator Questions & Answers given below include a hint and a link wherever possible to the relevant topic. This is helpful for users who are preparing for their exams, interviews, or professionals who would like to brush up on the fundamentals of Synchronous Generator. The alternator or synchronous generator's basic parts are the rotor which is DC excited winding and the stator three-phase winding. The salient pole and cylindrical or round rotor are two types of synchronous machines. In an alternator or synchronous generator various losses occur such as armature copper loss, field copper loss, brush contact loss, hysteresis and eddy current loss, friction, and windage loss. Alternators have brushes and slip rings and they also use a rotating coil. The failure of the prime mover, failure of the exciter, overloading, unbalanced loading, over-voltage, and over-speed are the abnormalities of an alternator or synchronous generator. The different methods to start synchronous motors are by using the pony motors, damper winding, a slip ring induction motor, and using a small DC machine coupled to it. The synchronizing can be done by using synchroscope and dark lamp methods. The reasons for the parallel operation of synchronous generators are handling larger loads, increased efficiency, increased system reliability, and maintenance that can be done without power dissipation. 1). Which one of the following methods is used to find voltage regulation? Direct loading method Ampere turns method EMF method All of the above Hint 2). In which one of the following rotors is preferred for low-speed alternators? Smooth cylindrical Salient pole Both a and b None of the above Hint 3). Which one of the following prime movers is used in the salient pole rotors? Electric motors Steam turbines Water turbines None of the above Hint 4). Which one of the following rotors is mechanically robust? Smooth cylindrical rotors Salient pole rotors Both a and b None of the above Hint 5). The small diameter and large axial length are the features of ___________________ rotor? Salient pole rotors Smooth cylindrical rotors Both a and b None of the above Hint 6). Which one of the following comes under copper losses? Eddy current Friction loss Brush contact loss None of the above Hint 7). What type of ring do alternators or synchronous generators have? Split ring commutator Slip rings, and brushes Both a and b None of the above Hint 8). Which one of the following is a type of single-layer winding? Chain winding Series compound Shunt compound None of the above Hint 9). When coil span is equal to pole pitch then that winding is known as _________________? Short pitched winding Full pitched winding Both a and b None of the above Hint 10). Which one of the following takes input from the stator? Alternator Capacitor Transformer None of the above Hint 11). ____________________ are the abnormalities of an alternator or synchronous generator? Overvoltage Over speed Overloading All of the above Hint 12). Which one of the following comes under stator fault? Earth fault Phase to phase Both a and b None of the above Hint 13). Which one of the following methods is used to start the synchronous motor? Pony motors Damper winding Both a and b None of the above Hint 14). In which one of the following the excitation is required? Synchronous generator Induction generator Both a and b None of the above Hint 15). Which one of the following has more efficiency? DC Generator Alternator Transformer None of the above Hint 16). Which one of the following is driven by a water turbine? Hydro generator Turbo alternators Both a and b None of the above Hint 17). What are the advantages of an armature as a stator? Easy cooling Easy insulation More efficient All of the above Hint 18). Which one of the following is an air-cooled turbo generator? TARI THRI THDF None of the above Hint 19). The undefined loss is the cause of _____________ loss? Copper loss Core loss Windage loss Stray loss Hint 20). Which one of the following takes input from the rotor? Generator Capacitor Transformer None of the above Hint 21). In which one of the following windings the end turns are shorter? Single layer windings Double layer windings Both a and b None of the above Hint 22). The speed of the diesel engine prime mover is ____________ RPM? 750 to 1500 750 to 4000 750 to 6000 750 to 7000 Hint 23). The cooling media is water in _______________ turbo generator? THDD THWW TARI None of the above Hint 24). What is the standard form of UEL? Under Excitation Limiter Under Exchange Limiter Under Excitation Less None of the above Hint 25). Which one of the following methods is also known as the ampere turn method? MMF method ZPF method Synchronous impedance method All of the above Hint Synchronous Generator MCQ for Quiz 26). In which one of the following generators, the speed range is up to 3000 RPM? Hydro generator Turbo alternators Both a and b None of the above Hint 27). In which one of the following generators the stator winding is directly water-cooled? TARI THRI THDF None of the above Hint 28). What are the main components of the turbine? Runner Labyrinths Shaft seal All of the above Hint 29). The specific speed of the Pelton wheel turbine is _____________ RPM? 10-50 rpm 60-300 rpm 300-1000 rpm None of the above Hint 30). Which one of the following supports a wider range of RPM? Alternator Capacitor Transformer None of the above Hint 31). The hysteresis and eddy current is the cause of _____________ loss? Copper loss Core loss Windage loss Stray loss Hint 32). The amount of water striking the runner divided by the amount of water supplied to the turbine is known as _____________ efficiency? Volumetric Overall Hydraulic Mechanical Hint 33). Which one of the following excitation systems is provided for a large-capacity generator? Static exciter Pilot exciter Brushless exciter None of the above Hint 34). The field current capacity is lower in _____________ SCR? High SCR Low SCR Both a and b None of the above Hint 35). What are the disadvantages of diesel engines? More noisy More expensive Both a and b None of the above Hint 36). In low head power plans the head of water is more than ___________________? 10000 meters 1.5 to 80 meters 40000 meters 80 to 500 meters Hint 37). What is the standard form of OEL? Over Excitation Limiter Over Exchange Limiter Overall Excitation Less None of the above Hint 38). The specific speed of the Francis turbine is _____________ RPM? 10-50 rpm 60-300 rpm 300-1000 rpm None of the above Hint 39). The rotor cooling is direct H2 in _____________ turbo generator? THDD THDF Both a and b None of the above Hint Read more about Synchronous Generator 40). Which one of the following supports a lesser range of RPM? Generator Capacitor Transformer None of the above Hint 41). In which one of the following windings, the phase induction is low? Single layer windings Double layer windings Both a and b None of the above Hint 42). Which one of the following is a hydrogen/water-cooled turbo generator? TARI THRI THDF None of the above Hint 43). The power available at the turbine shaft divided by net power supplied at the turbine entrance is known as _____________ efficiency? Volumetric Overall Hydraulic Mechanical Hint 44). In medium head power plans the head of water is more than ___________________? 10000 meters 20000 meters 40000 meters 80 to 500 meters Hint 45). What is the standard form of SCL? Simple Current Limiter Single Current Limiter Stator Current Limiter None of the above Hint 46). The figure shown below is a block diagram of ____________ generator? Turbine Hydraulic Synchronous and AVR None of the above Hint 47). In which one of the following exciters the length of the machine is longer? DC exciter AC exciter with stationary diodes Brushless exciter None of the above Hint 48). In which one of the following exciters does the control respond very fast? DC exciter AC exciter with stationary diodes Brushless exciter Static exciter Hint 49). The specific speed of the Kaplan turbine is _____________ RPM? 10-50 rpm 60-300 rpm 300-1000 rpm None of the above Hint 50). In which one of the following post-installation polarization is not required? Generator Alternator Transformer None of the above Hint Synchronous Generator MCQ for Interviews 51). In which one of the following generators the speed range is from 100 to 1000 RPM? Hydro generator Turbo alternators Both a and b None of the above Hint 52). In which one of the following generators the rotor/winding/stator core is directly hydrogen-cooled? TARI THRI Both a and b None of the above Hint 53). The speed of the gas turbine prime mover is ____________ RPM? 750 to 1500 750 to 4000 1500 to 3000 750 to 7000 Hint 54). The maximum capacity of the THDF turbo generator is _______________? 150 Mw 250 Mw 350 Mw 500 Mw Hint 55). The power developed by the runner divided by net power supplied at the turbine entrance is known as _____________ efficiency? Volumetric Overall Hydraulic Mechanical Hint 56). What are the advantages of diesel engines? More efficient More reliable More durable All of the above Hint 57). In high-head power plans the head of water is more than ___________________? 10000 meters 20000 meters 40000 meters 500 meters Hint 58). What are the advantages of hydraulic power plants? Long plant life Pollution free Operating cost is very low All of the above Hint 59). The cooling media is hydrogen in _______________ turbo generator? THDD THWW TARI None of the above Hint 60). Which one of the following can’t be used to charge a dead battery? Generator Alternator Transformer None of the above Hint 61). In which one of the following windings the rotor losses are lower? Double layer windings Single layer windings Both a and b None of the above Hint 62). Which one of the following rotors has large projecting poles? Smooth cylindrical rotors Salient pole rotors Both a and b None of the above Hint 63). Which one of the following comes under mechanical losses? Eddy current Friction loss Brush contact loss None of the above Hint 64). In which one of the following the voltage variation is possible? Induction generator Synchronous generator Both a and b None of the above Hint 65). In which one of the following generators the stator winding is indirectly air-cooled? TARI THRI THDF Both a and b Hint 66). The air friction loss in the cooling fan mounted on the rotor shaft is the cause of _____________ loss? Mechanical loss Core loss Windage loss Stray loss Hint 67). The cooling media is air in _______________ turbo generator? THDD THWW TARI None of the above Hint 68). The power available at the turbine shaft divided by power developed by the runner is known as _____________ efficiency? Volumetric Overall Hydraulic Mechanical Hint 69). Which one of the following excitation systems is provided for the low-capacity generator? Static exciter Pilot exciter Brushless exciter None of the above Hint 70). In which one of the following is the brush durability higher? Generator Alternator Transformer None of the above Hint 71). In which one of the following generators the rating is up to 1000 Mw? Turbo alternators Hydro generator Both a and b None of the above Hint 72). In which one of the following generators the rotor winding/stator core is directly air-cooled? TARI THRI THDF Both a and b Hint 73). In which one of the following exciters the response ratio selection is flexible? DC exciter AC exciter with stationary diodes Brushless exciter Static exciter Hint 74). The static excitation system consists of ________________? Rectifier transformer Field discharge equipment Both a and b None of the above Hint 75). In which one of the following windings, the synchronous winding factor is lower? Double layer windings Single layer windings Both a and b None of the above Hint Synchronous Generator MCQ for Students 76). The maximum capacity of the THRI turbo generator is _______________? 150 Mw 250 Mw 350 Mw 500 Mw Hint 77). Which one of the following excitation systems is provided for a high-capacity generator? Static exciter Pilot exciter Brushless exciter None of the above Hint 78). In which one of the following exciter the length of the machine short? Static exciter DC exciter Both a and b None of the above Hint 79). The stator cooling is indirect in _____________ turbo generator? TARI THRI Both a and b None of the above Hint 80). Which one of the following is generally larger in size? Generator Alternator Transformer None of the above Hint 81). In which one of the following the efficiency, cost, and inertia are high? Induction generator Synchronous generator Both a and b None of the above Hint 82). The friction loss in bearings is the cause of _____________ loss? Mechanical loss Core loss Windage loss Stray loss Hint 83). _______________ are the parameters of any generator decided by SCR? Stability limit Size, efficiency, cost Voltage regulation All of the above Hint 84). The maximum capacity of the TARI turbo generator is _______________? 150 Mw 250 Mw 350 Mw 500 Mw Hint 85). In which one of the following windings the back EMF is more sinusoidal? Single layer windings Double layer windings Both a and b None of the above Hint 86). Which one of the following comes under rotor fault? Earth fault Phase to phase Both a and b None of the above Hint 87). The speed of the steam turbine prime mover is ____________ RPM? 750 to 1500 750 to 4000 1500 to 3000 3000 Hint 88). Which one of the following is a hydrogen-cooled turbo generator? TARI THRI THDF None of the above Hint 89). Which one of the following methods is also known as the Potier triangle method? MMF method ZPF method Synchronous impedance method All of the above Hint 90). Which one of the following has a commutator mechanism? DC Generator Alternator Transformer None of the above Hint 91). In which one of the following rotors the air gap is non-uniform? Smooth cylindrical Salient pole Both a and b None of the above Hint 92). Which one of the following is driven by a steam turbine? Hydro generator Turbo alternators Both a and b None of the above Hint 93). In which one of the following generators the rating is up to 750 Mw? Hydro generator Turbo alternators Both a and b None of the above Hint 94). What are the main functions of an automatic voltage regulator system? Limiters Terminal voltage control Both a and b None of the above Hint 95). Which one of the following windings is more difficult to manufacture? Single layer windings Double layer windings Both a and b None of the above Hint 96). In which one of the following the isolated operation is possible? Synchronous generator Induction generator Both a and b None of the above Hint 97). Which one of the following comes under magnetic losses? Eddy current Friction loss Brush contact loss None of the above Hint 98). Which one of the following prime movers is used in the smooth cylindrical rotors? Electric motors Steam turbines Water turbines None of the above Hint 99). Which one of the following methods is also known as the EMF method? MMF method ZPF method Synchronous impedance method All of the above Hint 100). Which one of the following has less RPM? DC Generator Alternator Transformer None of the above Hint For More MCQs DC Generator Question & Answers Time's up
