DC Generator Question & AnswersNovember 1, 2021 By Wat Electrical This article lists 100 DC generator MCQs for engineering students. All the DC generator Questions & Answers given below include a solution and 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 their fundamentals on the DC generator topic which is core in Electrical Engineering.Generators are separate electrical devices or machines, used to supply electricity once electricity from the nearby grid is not available. These are classified into two types based on their output like AC generators and DC generators. These generators play a key role by providing backup power to homes, businesses, industries, organizations when there is no power supply. The main function of Generators is to change the energy from mechanical or chemical into electrical.1). For large DC loads, we connect DC generators in-------- Series Parallel Straight line Both a & c None Hint2). For connecting two DC generators in parallel they should have ---? Different voltage characteristics Same Current characteristics Same Drooping voltage characteristics Same r.p.m. None Hint3). Lap windings in DC generators are used for---? High voltage and High current High voltage and low current Low voltage and High current Low voltage and low current None Hint4). For parallel connected Dc generators, the summation of the current carried by them is equal to---? Total Armature current Load current Applied source value All of the above. None Hint5). For the DC generator, the resistance of ------is critical? Load. Brushes Field Shaft None Hint6). In an idle DC generator, the % of regulation is...? 0% 5% 10% 50% None Hint7). The Field coils of the DC generator are made up of ----? Steel Copper Aluminum Iron None Hint8). The first electrical generator was invented by…? Michael Faraday's August Toepler Paramahamsa Tewari John Read None Hint9). DC generators are categorized into ….. Types depending on the field excitation methods? 2 3 4 5 None Hint10). The material used to make the core lamination is? Carbon Copper Silver Silicon steel None Hint11). If the generators are need to run parallel then which of the following type is used? Series generators Permanent magnet Shunt generators Compound generators None Hint12). If the critical resistance of a DC generator is increased then…? Speed will be increased Speed will be decreased Speed resistance will be increased Speed resistance will be decreased None Hint13). Welding generator includes….winding? Delta Lap Wave Duplex Wave None Hint14). The armature winding’s resistance mainly depends on…? Temperature Voltage Current Number of conductors used None Hint15). Which of the following bearings are used to give support to the rotor shaft? Bush Ball Needle Magnetic None Hint16). The mechanical losses within DC generators are the main function of? Voltage Current Resistance Speed None Hint17). The flow of current to the external circuit in a DC generator can be given through? Slip rings Commutator Windings Bearings None Hint18). The material used to make a brushless dc machine is? Iron Copper Aluminum Carbon None Hint19). Which of the following material is used for commutator brushes? Carbon Aluminum Copper Iron None Hint20). When the armature is….wound then equalizer rings are necessary? Lap Wave Duplex Delta None Hint21). Long shunt compound generator is used in automobiles for…? Battery charging Increase the performance Decrease the performance Control the speed None Hint22). A DC generator can be used like a…? Rectifier Rotating amplifier Controlling device Power pump None HintPlease refer to this link to know more about DC Generators23). The field resistance is the critical resistance of….? DC Motor DC Generator DC Machines AC Machines None Hint24). The working principle of dc generator is…? Ohms law Lenz’s law Faradays induction law Lorentz force None Hint25). The regulation used in DC generators is? 1% 10% 50% 100% None HintDC Generator MCQs for Interviews26). Which generator is used for long transmission line feeding? Flat compound Over compound Series Shunt None Hint27). When a series generator is self-excited? If the current at load is zero If the current at load is not zero If the maximum current is there at load If the minimum current is there at load None Hint28). How the lamination of a DC generator can be done to…? Decrease the bulk By insulating core By decreasing eddy current loss By insulating the core None Hint29). In a 4-pole DC machine, the direction of all the poles are…? South poles North poles From north to south Alternate poles are south & north None Hint30). In a DC generator, the generated emf is directly proportional to….? Armature speed Flux Pole Windings None Hint31). Which of the following generator’s terminal voltage changes when load changes? Series Shunt Series compound Shunt compound None Hint32). In which type of generator, the poorest voltage regulation is there? Shunt Differential compounded Series Shunt compound None Hint33). The connection of field windings in the separately excited generator is? Series with circuit Series with source Shunt with source Shunt with circuit None Hint34). The brushes in DC generators are made with…? Copper Bronze Carbon & Graphite Silver None Hint35). The connection of inter pole winding can be done in series with….winding? Field Wave Armature Lap None Hint36). A DC shunt generator is an exciter for…? Turbogenerator Series generator Shunt generator Compound None Hint37). In electrical machines, which of the following material is used to decrease hysteresis loss…? Cast iron Silicon steel Tungsten steel Aluminum None Hint38). When the DC generator’s polarity is reversed, then,? Field current can be reversed Increases field current Motor speed will be increased Field current can be increased None Hint39). Lap winding is used in which machines? High current & high voltage High current & low voltage Low current & Low voltage None Hint40). How is the magnetic field generated in DC generators? Electromagnets Windings Permanent magnets Yoke None Hint41). How many poles are there in small DC machines? 2 3 4 5 None Hint42). The most commonly used DC machines are…..? 3 Pole 4 Pole 6 Pole 8 Pole None Hint43). How many parallel paths are available in triplex wave winding…..? 2 4 5 6 None Hint44). The type of generator used for welding is.? Cumulatively compounded generator Series generator Shunt generator Differentially compounded generator None Hint45). Stray loss within a DC machine is the sum of …… and …..? Copper & mechanical losses Mechanical & iron losses Iron & armature copper losses Mechanical & iron losses None Hint46). Which of the following part provides DC for a DC generator? Commutator Eyebolt Brushes Windings None Hint47). In commutator segments, which of the following material is used? Copper Mica Carbon Paper None Hint48). When dummy coils are used in a DC generator? To decrease eddy current losses For voltage amplification To improve flux density For providing mechanical balance to the rotor None Hint49). Which of the following loss has the highest proportion within DC generators? Eddy current loss Hysteresis loss Field copper loss Armature loss None Hint50). Which loss will be changed with the load current in DC machines? Field copper loss Windage loss Eddy current loss Armature copper loss None HintDC Generator MCQs for Exams51). What is the function of the fractional pitch in the DC generator? Increases voltage Sparking can be reduced Improves cooling Gives protection None Hint52). Why aluminum is not used as a winding within DC machines? It is not strong It uses more space Expensive Less resistivity None Hint53). What is the function of frog leg winding in a DC machine? It eliminates the compensating winding It eliminates equalizers within the winding Reactance voltage Controls the machine speed None Hint54). In a DC machine, the armature MMF signal shape is? Sinusoidal Triangular Square Pulsating None Hint55). Which of the following is used to get sparkles communication? Winding Inter poles Brushes Eyebolt None Hint56). When does a series generator excite? When load current is not equal to zero When load current is zero Once the supply is provided Once the speed is increased None Hint57). Once the field winding resistance in a DC generator is increased then the o/p voltage will be….? Decreased Decreased Zero None of the above None Hint58). When the generator runs on no-load then which of the following type generator will have negligible terminal voltage? Shunt generator Series generator Separately excited Permanent magnet None Hint59). The armature MMF in a DC machine is directed through the…axis? Polar Interpolar Brush None of the above None Hint60). The armature winding in DC machines is located on the rotor for…? Voltage generation Communication Generation of voltage Controlling the motor speed None Hint61). A machine that is used to change the energy from mechanical to electrical is called? Generator Motor Transformer Battery None Hint62). Which generator provides stable voltage for different loads? Level compounded Series Permanent magnet Shunt generators None Hint63). The reciprocal of reluctance is known as? Resistance Series Inductance Permeance None Hint64). Which of the following brush has less voltage drop? Carbon Yoke pole armature Graphite Metal graphite None Hint65). Which of the following component is used to provide DC for a DC generator? Commutator Eyebolt Windings Rotor None Hint66). The brushes within a commutator mainly depend on…? Commutator Windings Eyebolt Based on controlling current None Hint67). How the magnetic field can be generated within DC machines? Commutator Electromagnets Eyebolt Windings None Hint68). In commutator segments, the insulating material used is…? Paper Graphite Mica Dielectric None Hint69). Which of the following material is used to make brushes? Copper Carbon Aluminum Iron None Hint70). The field coils are made with? Copper Mica Aluminum Carbon None Hint71). What is the name of the first electrical generator? Thomson Antonio Dynamo Faraday None Hint72). The name of the first electromagnetic generator is…? Faraqday Disc Dynamo Antonio Faraday None Hint73). The electromagnetic generator was invented in which year…? 1820 1835 1831 1905 None Hint74). The function of an electric generator is quite opposite of…? Electric Motor Turbine Transformer Fuses None Hint75). How many categories are there in electromagnetic generators? 2 3 4 5 None HintDC Generator MCQs for Quiz76). In a DC machine, the external frame is called as? Rotor Stator Yoke Commutator None Hint77). How many principal components are there in DC machines? 2 3 5 6 None Hint78). How the poles are connected to the yoke in DC machines? Using Welding or Bolts Using Windings Using Wires Using Magnets None Hint79). The field system in DC generators is used to generate? Electromagnetic field Uniform magnetic field Electric field Magnetic & Electric Fields None Hint80). Practical DC machines include….? Air gaps Eyebolts Windings Commutators None HintPlease refer to this link to know more about DC Machine81). Which of the following device is used to convert AC to DC and DC to AC? Commutator Eyebolts Windings Brushes None Hint82). How many types of losses are there in the DC machine? 2 3 4 5 None HintPlease refer to this link to know more about Types of Losses in DC Machine83). The principle used by the generator to convert the energy is? E.M.F Magnetic Induction Flemming’s left-hand rule Uniform magnetic field None Hint84). In a generator, when the power loss occurs within the armature winding then it is known as? Copper loss Eddy current loss Mechanical loss Hysteresis loss None Hint85). A heat loss is called as? Copper loss Hysteresis loss Mechanical loss Eddy current loss None Hint86). Which of the following construction is the main difference between practical and normal generators? Armature Brushes Yoke Stator None Hint87). In the series-wound type, which of the following are connected with the armature in series?. Field windings Brushes Load Stator None Hint88). In a shunt-wound generator, the field coils are connected in shunt with…?. Load Field windings Stator Rotor None Hint89). Which of the following occurs when the load changes in a generator? Voltage regulation Voltage control Current control Current regulation None Hint90). Which of the following is used for increasing/reducing terminal voltage? Current control Voltage regulation Voltage control Current regulation None Hint91). When the generators are connected in parallel then they provide? More current More voltage More power More resistance None Hint92). The special-purpose type DC generators are called as? Metadyne Amplidyne Alternator Rheostat None Hint93). Armature types in DC generator are? 2 3 4 5 None Hint94). Once the voltage is provided to the main windings then it is known as? Self Excitation Field Excitation Excitation Voltage regulation None Hint95). The generator which gets current from an external source? Series wound Separately excited Self-excited Shunt-wound None Hint96). Which of the following generator uses their o/p voltage to strengthen field coils? Self-excited Series wound Shunt-wound Separately excited None Hint97). The output changes with load currents directly in….generators? Self-excited Shunt-wound Separately excited Series wound None Hint98). The distribution of actual flux in dc generators mainly depends on…? Air gap size Windings Yoke Rotor None Hint99). Which of the following material is harder in a commutator? Mica Copper Silicon Silver None Hint100). The voltage build-up in a shunt generator can be restricted by? Heat generated Limitation of speed Insulation Iron Saturation None Hint Time's up
