DC Generator Question & Answers November 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 Hint 2). For connecting two DC generators in parallel they should have ---? Different voltage characteristics Same Current characteristics Same Drooping voltage characteristics Same r.p.m. Hint 3). 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 Hint 4). 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. Hint 5). For the DC generator, the resistance of ------is critical? Load. Brushes Field Shaft Hint 6). In an idle DC generator, the % of regulation is...? 0% 5% 10% 50% Hint 7). The Field coils of the DC generator are made up of ----? Steel Copper Aluminum Iron Hint 8). The first electrical generator was invented by…? Michael Faraday's August Toepler Paramahamsa Tewari John Read Hint 9). DC generators are categorized into ….. Types depending on the field excitation methods? 2 3 4 5 Hint 10). The material used to make the core lamination is? Carbon Copper Silver Silicon steel Hint 11). If the generators are need to run parallel then which of the following type is used? Series generators Permanent magnet Shunt generators Compound generators Hint 12). 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 Hint 13). Welding generator includes….winding? Delta Lap Wave Duplex Wave Hint 14). The armature winding’s resistance mainly depends on…? Temperature Voltage Current Number of conductors used Hint 15). Which of the following bearings are used to give support to the rotor shaft? Bush Ball Needle Magnetic Hint 16). The mechanical losses within DC generators are the main function of? Voltage Current Resistance Speed Hint 17). The flow of current to the external circuit in a DC generator can be given through? Slip rings Commutator Windings Bearings Hint 18). The material used to make a brushless dc machine is? Iron Copper Aluminum Carbon Hint 19). Which of the following material is used for commutator brushes? Carbon Aluminum Copper Iron Hint 20). When the armature is….wound then equalizer rings are necessary? Lap Wave Duplex Delta Hint 21). Long shunt compound generator is used in automobiles for…? Battery charging Increase the performance Decrease the performance Control the speed Hint 22). A DC generator can be used like a…? Rectifier Rotating amplifier Controlling device Power pump Hint Please refer to this link to know more about DC Generators 23). The field resistance is the critical resistance of….? DC Motor DC Generator DC Machines AC Machines Hint 24). The working principle of dc generator is…? Ohms law Lenz’s law Faradays induction law Lorentz force Hint 25). The regulation used in DC generators is? 1% 10% 50% 100% Hint DC Generator MCQs for Interviews 26). Which generator is used for long transmission line feeding? Flat compound Over compound Series Shunt Hint 27). 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 Hint 28). 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 Hint 29). 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 Hint 30). In a DC generator, the generated emf is directly proportional to….? Armature speed Flux Pole Windings Hint 31). Which of the following generator’s terminal voltage changes when load changes? Series Shunt Series compound Shunt compound Hint 32). In which type of generator, the poorest voltage regulation is there? Shunt Differential compounded Series Shunt compound Hint 33). The connection of field windings in the separately excited generator is? Series with circuit Series with source Shunt with source Shunt with circuit Hint 34). The brushes in DC generators are made with…? Copper Bronze Carbon & Graphite Silver Hint 35). The connection of inter pole winding can be done in series with….winding? Field Wave Armature Lap Hint 36). A DC shunt generator is an exciter for…? Turbogenerator Series generator Shunt generator Compound Hint 37). In electrical machines, which of the following material is used to decrease hysteresis loss…? Cast iron Silicon steel Tungsten steel Aluminum Hint 38). 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 Hint 39). Lap winding is used in which machines? High current & high voltage High current & low voltage Low current & Low voltage Hint 40). How is the magnetic field generated in DC generators? Electromagnets Windings Permanent magnets Yoke Hint 41). How many poles are there in small DC machines? 2 3 4 5 Hint 42). The most commonly used DC machines are…..? 3 Pole 4 Pole 6 Pole 8 Pole Hint 43). How many parallel paths are available in triplex wave winding…..? 2 4 5 6 Hint 44). The type of generator used for welding is.? Cumulatively compounded generator Series generator Shunt generator Differentially compounded generator Hint 45). Stray loss within a DC machine is the sum of …… and …..? Copper & mechanical losses Mechanical & iron losses Iron & armature copper losses Mechanical & iron losses Hint 46). Which of the following part provides DC for a DC generator? Commutator Eyebolt Brushes Windings Hint 47). In commutator segments, which of the following material is used? Copper Mica Carbon Paper Hint 48). 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 Hint 49). Which of the following loss has the highest proportion within DC generators? Eddy current loss Hysteresis loss Field copper loss Armature loss Hint 50). Which loss will be changed with the load current in DC machines? Field copper loss Windage loss Eddy current loss Armature copper loss Hint DC Generator MCQs for Exams 51). What is the function of the fractional pitch in the DC generator? Increases voltage Sparking can be reduced Improves cooling Gives protection Hint 52). Why aluminum is not used as a winding within DC machines? It is not strong It uses more space Expensive Less resistivity Hint 53). 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 Hint 54). In a DC machine, the armature MMF signal shape is? Sinusoidal Triangular Square Pulsating Hint 55). Which of the following is used to get sparkles communication? Winding Inter poles Brushes Eyebolt Hint 56). 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 Hint 57). 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 Hint 58). 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 Hint 59). The armature MMF in a DC machine is directed through the…axis? Polar Interpolar Brush None of the above Hint 60). The armature winding in DC machines is located on the rotor for…? Voltage generation Communication Generation of voltage Controlling the motor speed Hint 61). A machine that is used to change the energy from mechanical to electrical is called? Generator Motor Transformer Battery Hint 62). Which generator provides stable voltage for different loads? Level compounded Series Permanent magnet Shunt generators Hint 63). The reciprocal of reluctance is known as? Resistance Series Inductance Permeance Hint 64). Which of the following brush has less voltage drop? Carbon Yoke pole armature Graphite Metal graphite Hint 65). Which of the following component is used to provide DC for a DC generator? Commutator Eyebolt Windings Rotor Hint 66). The brushes within a commutator mainly depend on…? Commutator Windings Eyebolt Based on controlling current Hint 67). How the magnetic field can be generated within DC machines? Commutator Electromagnets Eyebolt Windings Hint 68). In commutator segments, the insulating material used is…? Paper Graphite Mica Dielectric Hint 69). Which of the following material is used to make brushes? Copper Carbon Aluminum Iron Hint 70). The field coils are made with? Copper Mica Aluminum Carbon Hint 71). What is the name of the first electrical generator? Thomson Antonio Dynamo Faraday Hint 72). The name of the first electromagnetic generator is…? Faraqday Disc Dynamo Antonio Faraday Hint 73). The electromagnetic generator was invented in which year…? 1820 1835 1831 1905 Hint 74). The function of an electric generator is quite opposite of…? Electric Motor Turbine Transformer Fuses Hint 75). How many categories are there in electromagnetic generators? 2 3 4 5 Hint DC Generator MCQs for Quiz 76). In a DC machine, the external frame is called as? Rotor Stator Yoke Commutator Hint 77). How many principal components are there in DC machines? 2 3 5 6 Hint 78). How the poles are connected to the yoke in DC machines? Using Welding or Bolts Using Windings Using Wires Using Magnets Hint 79). The field system in DC generators is used to generate? Electromagnetic field Uniform magnetic field Electric field Magnetic & Electric Fields Hint 80). Practical DC machines include….? Air gaps Eyebolts Windings Commutators Hint Please refer to this link to know more about DC Machine 81). Which of the following device is used to convert AC to DC and DC to AC? Commutator Eyebolts Windings Brushes Hint 82). How many types of losses are there in the DC machine? 2 3 4 5 Hint Please refer to this link to know more about Types of Losses in DC Machine 83). The principle used by the generator to convert the energy is? E.M.F Magnetic Induction Flemming’s left-hand rule Uniform magnetic field Hint 84). 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 Hint 85). A heat loss is called as? Copper loss Hysteresis loss Mechanical loss Eddy current loss Hint 86). Which of the following construction is the main difference between practical and normal generators? Armature Brushes Yoke Stator Hint 87). In the series-wound type, which of the following are connected with the armature in series?. Field windings Brushes Load Stator Hint 88). In a shunt-wound generator, the field coils are connected in shunt with…?. Load Field windings Stator Rotor Hint 89). Which of the following occurs when the load changes in a generator? Voltage regulation Voltage control Current control Current regulation Hint 90). Which of the following is used for increasing/reducing terminal voltage? Current control Voltage regulation Voltage control Current regulation Hint 91). When the generators are connected in parallel then they provide? More current More voltage More power More resistance Hint 92). The special-purpose type DC generators are called as? Metadyne Amplidyne Alternator Rheostat Hint 93). Armature types in DC generator are? 2 3 4 5 Hint 94). Once the voltage is provided to the main windings then it is known as? Self Excitation Field Excitation Excitation Voltage regulation Hint 95). The generator which gets current from an external source? Series wound Separately excited Self-excited Shunt-wound Hint 96). Which of the following generator uses their o/p voltage to strengthen field coils? Self-excited Series wound Shunt-wound Separately excited Hint 97). The output changes with load currents directly in….generators? Self-excited Shunt-wound Separately excited Series wound Hint 98). The distribution of actual flux in dc generators mainly depends on…? Air gap size Windings Yoke Rotor Hint 99). Which of the following material is harder in a commutator? Mica Copper Silicon Silver Hint 100). The voltage build-up in a shunt generator can be restricted by? Heat generated Limitation of speed Insulation Iron Saturation Hint Time is Up! Time's up
