Transmission Distribution Question & Answers May 9, 2023 By Wat Electrical This article lists 100 Transmission Distribution MCQs for engineering students. All the Transmission Distribution Questions & Answers below include a hint and a link to the relevant topic wherever possible. This is helpful for users who are preparing for their exams, interviews, or professionals who would like to brush up on the fundamentals of Transmission Distribution. Transmission and distribution are two key components of the electrical power system that work together to deliver electricity to consumers. Transmission refers to the movement of high-voltage electricity from power plants to local substations, typically over long distances using high-voltage power lines. This process is necessary because electricity generated at power plants is typically at a very high voltage, which is too dangerous for most consumers to use directly. Transmission systems are designed to minimize the loss of electrical energy as it travels over long distances, typically by using HVDC lines or HVAC lines. Distribution, on the other hand, refers to the process of delivering lower-voltage electricity from local substations to individual consumers. This typically involves the use of medium-voltage power lines, transformers, and other equipment to reduce the voltage of the electricity to safe levels for use in homes, businesses, and other facilities. Overall, transmission and distribution systems work together to ensure that electrical power is delivered reliably and efficiently to consumers across large geographic areas. 1). What is the purpose of transformers in the electrical power system? To step up or step down the voltage of the electricity To convert AC to DC power To transmit electricity over long distances None of the above Hint 2). Which component of the electrical power system is responsible for regulating the voltage of the electricity? Transformers Substations Power plants None of the above Hint 3). What does the term "HVAC" stand for in the context of electrical power transmission? High-voltage air conditioning High-voltage alternating current High-voltage direct current High-voltage electrical system Hint 4). What is the typical voltage range used for HVAC transmission lines? Less than 100 volts 100-500 volts 500-1000 volts More than 1000 volts Hint 5). What is the primary reason why HVAC transmission lines are preferred over HVDC lines in some situations? They experience less power loss over long distances They are more efficient at converting AC to DC power They are less expensive to install and maintain They are more reliable in extreme weather conditions Hint 6). Which of the following is a disadvantage of using HVAC transmission lines? a) They are more expensive than HVDC lines They experience more power loss over long distances They are less reliable in extreme weather conditions They are less efficient at converting AC to DC power Hint 7). What is the full form of HVDC? High Voltage Direct Current High Voltage Differential Current High Velocity Direct Current High Velocity Differential Current Hint 8). Which of the following is not an advantage of HVDC transmission? Lower line losses Lower cost of transmission Smaller right-of-way requirements Reduced interference with communication lines Hint 9). Which of the following is a disadvantage of HVDC transmission? Limited transmission capacity Limited transmission distance Higher line losses than AC transmission Cannot be used for underground cables Hint 10). Which of the following is responsible for moving electricity from power plants to local substations? Distribution Transmission Both a and b None of the above Hint 11). What is a converter station in an HVDC system? A station that converts AC to DC A station that converts DC to AC A station that regulates the voltage of the transmission line A station that monitors the transmission line for faults Hint 12). Which of the following is not a type of HVDC transmission system? Line-commutated converter (LCC) system Voltage-source converter (VSC) system Current-source converter (CSC) system Phase-commutated converter (PCC) system Hint 13). Which of the following is a type of HVDC cable? XLPE cable PILC cable PVC cable Paper-insulated lead-covered cable Hint 14). What does UHVDC stand for? Ultra High Voltage Direct Current Ultra High Velocity Direct Current Ultra High Voltage Distribution Current Ultra High Frequency Direct Current Hint 15). What is the typical voltage level of a UHVDC transmission system? 500-1000 kV 1000-2000 kV 2000-3000 kV 3000-4000 kV Hint 16). What is the main challenge associated with UHVDC technology? High cost Technical complexity Environmental impact Safety concerns Hint 17). Which country was the first to develop and deploy UHVDC technology? China Japan United States Germany Hint 18). What is the typical transmission capacity of a UHVDC transmission line? 1000-2000 MW 2000-4000 MW 4000-6000 MW 6000-8000 MW Hint 19). What is the maximum transmission distance achieved by a UHVDC transmission line to date? 1000 km 2000 km 3000 km 4000 km Hint 20). What is the voltage level of electricity typically used for transmission? High voltage Low voltage Medium voltage None of the above Hint 21). What is the primary component of a UHVDC transmission system? Transformer Circuit breaker Converter station Insulator Hint 22). A power plant generates 10 MW of power at 25 kV. If the power is to be transmitted over a distance of 100 km to a substation, what is the minimum voltage level that should be used to minimize power loss? 25 kV 50 kV 100 kV 500 kV Hint 23). A substation receives power at 500 kV and is responsible for distributing it to individual consumers at 12 kV. If the substation is located 10 km from the consumers, what size of transformer is needed to step down the voltage to 12 kV? 40 kVA 4167 kVA 50,000 kVA 500,000 kVA Hint 24). A distribution system experiences a voltage drop of 5% between the substation and a consumer's home due to the resistance of the power lines. If the voltage at the substation is 120 V, what is the voltage at the consumer's home? 114 V 118 V 123 V 126 V Hint 25). A transmission line experiences a power loss of 10 MW when transmitting 100 MW of power over a distance of 200 km. What is the power loss per kilometer of the transmission line? 5 kW/km 25 kW/km 50 kW/km 100 kW/km Hint Transmission Distribution MCQ for Quiz 26). What is the maximum amount of power that can be transmitted over a power line with a voltage of 500 kV and a current of 1000 A? 500 MW 5000 MW 50,000 MW 500,000 MW Hint 27). A power plant generates electricity at a voltage of 20 kV and a power output of 100 MW. If the power is transmitted over a distance of 100 km using a transmission line with a resistance of 0.5 Ω/km, what is the voltage at the receiving end of the line? 20 kV 15.7 kV 10 kV 5.7 kV Hint 28). A distribution line has a voltage of 12 kV and a length of 5 km. If the line has a resistance of 0.2 Ω/km and a load of 1000 kW is connected to the end of the line, what is the voltage at the end of the line? 11.3 kV 10.8 kV 10.3 kV 9.8 kV Hint 29). A distribution line has a voltage of 4160 V and a length of 2 miles. If the line has a resistance of 0.2 Ω/mile and a load of 500 kW is connected to the end of the line, what is the voltage at the end of the line? 3835 V 3760 V 3685 3610 V Hint 30). Which of the following is typically used for reducing the voltage of electricity in distribution systems? HVDC lines HVAC lines Transformers None of the above Hint 31). What is the main difference between HVAC and HVDC? The type of current used The voltage level used The frequency of the current used The type of equipment used Hint 32). Which of the following is an advantage of HVDC over HVAC? Lower transmission losses Lower equipment cost Higher voltage levels Greater system stability Hint 33). Which of the following is a disadvantage of HVDC compared to HVAC? Higher transmission losses Higher equipment cost Lower voltage levels Less system stability Hint 34). What is the typical frequency of power used in AC power systems? 50 Hz or 60 Hz 100 Hz or 120 Hz 200 Hz or 240 Hz 400 Hz or 480 Hz Hint 35). What is the typical voltage level used in high-voltage power transmission systems? 120 V 240 V 1 kV 100 kV or higher Hint 36). Which of the following materials is commonly used for overhead transmission and distribution lines? Copper Aluminum Silver Gold Hint 37). In a power system single-line diagram, what does a circle represent? A generator A transformer A transmission line A busbar Hint 38). Which of the following is NOT a common probability distribution? Normal distribution Poisson distribution Binomial distribution Linear distribution Hint 39). Which of the following is true about the mean of a normal distribution? It is always zero It is always positive It is always negative It can be any real number Hint 40). Which of the following is responsible for delivering lower-voltage electricity from local substations to individual consumers? Transmission Distribution Both a and b None of the above Hint 41). Which type of power line is typically used for transmission over long distances? Low-voltage power lines Medium-voltage power lines High-voltage direct current lines High-voltage alternating current lines Hint 42). Which type of power line is typically used for distribution to individual consumers? Low-voltage power lines Medium-voltage power lines High-voltage direct current lines High-voltage alternating current lines Hint 43). Which of the following is responsible for minimizing the loss of electrical energy during transmission over long distances? Transformers High-voltage direct current lines Low-voltage power lines None of the above Hint 44). Which of the following is not a component of the transmission system? Power plants High-voltage power lines Transformers Medium-voltage power lines Hint 45). Which of the following is not a component of the distribution system? Transformers Medium-voltage power lines Low-voltage power lines High-voltage power lines Hint 46). Which of the following is true regarding high-voltage direct current lines? They are more efficient for transmitting electricity over long distances than HVAC lines They are more efficient for transmitting electricity over short distances than HVAC lines They are less reliable than HVAC lines Hint 47). Which of the following is true regarding the use of transformers in the electrical power system? They are used to increase the voltage of electricity during transmission They are used to decrease the voltage of electricity during distribution They are used to increase the voltage of electricity during distribution They are not used in the electrical power system Hint 48). Which of the following is true regarding the reliability of the electrical power system? Reliability is only affected by the generation of electricity Reliability is only affected by the transmission of electricity Reliability is only affected by the distribution of electricity Reliability is affected by all components of the electrical power system Hint 49). Which of the following is a component of the transmission system? Medium-voltage power lines Transformers High-voltage direct current lines None of the above Hint 50). Which of the following is a component of the distribution system? Low-voltage power lines High-voltage alternating current lines Substations All of the above Hint Transmission Distribution MCQ for Exams 51). Which of the following is a typical application of HVDC technology? Power transmission over long distances Power distribution within a city Power generation from renewable sources None of the above Hint 52). What is the advantage of HVDC over HVAC for long distance power transmission? Higher transmission efficiency Lower transmission losses Lower transmission cost All of the above Hint 53). Which of the following is NOT a type of HVDC converter? LCC VSC MCC UHVDC Hint 54). What is the typical voltage range for HVDC transmission? 50-100 kV 100-500 kV 500-1000 kV 1000-2000 kV Hint 55). Which of the following is a disadvantage of HVDC transmission? Higher initial cost Limited transmission distance Higher maintenance cost None of the above Hint 56). What is the primary component of an HVDC transmission system? Transformer Circuit breaker Converter station Insulator Hint 57). Which of the following is a potential benefit of using HVDC for renewable energy integration? Smaller converter stations Increased transmission distance Higher transmission efficiency All of the above Hint 58). What is the typical transmission capacity of an HVDC line? 100-500 MW 500-1000 MW 1000-5000 MW 5000-10000 MW Hint 59). What is the main advantage of UHVDC over traditional HVDC? Higher transmission efficiency Lower transmission losses Longer transmission distance All of the above Hint 60). Which of the following distributions is used to model the number of successes in a fixed number of independent trials? Poisson distribution Normal distribution Binomial distribution Exponential distribution Hint 61). Which of the following distributions is used to model the time between independent events occurring at a constant rate? Poisson distribution Normal distribution Exponential distribution Uniform distribution Hint 62). Which of the following is true about the standard deviation of a normal distribution? It is always zero It is always positive It is always negative It can be any real number Hint 63). Which of the following distributions is used to model rare events? Poisson distribution Normal distribution Binomial distribution Exponential distribution Hint 64). Which of the following distributions is used to model the outcome of a continuous random variable? Poisson distribution Normal distribution Binomial distribution Geometric distribution Hint 65). Which of the following is true about the probability density function (PDF) of a continuous distribution? It can take on negative values It is always positive It is always zero It can be any real number Hint 66). Which of the following distributions is used to model the amount of time until a specific event occurs? Poisson distribution Normal distribution Binomial distribution Weibull distribution Hint 67). Which of the following is NOT a common application of the Weibull distribution? Reliability engineering Failure analysis Survival analysis Binomial regression Hint 68). Which of the following parameters of the Weibull distribution determines the shape of the distribution? Scale parameter Shape parameter Location parameter Probability parameter Hint 69). What is the range of possible values for the shape parameter of the Weibull distribution? Any positive real number Any non-negative real number Any real number Any integer Hint 70). Which of the following is true about the Weibull distribution when the shape parameter is less than 1? The distribution is symmetric The distribution is skewed to the left The distribution is skewed to the right The distribution is bimodal Hint 71). What is the characteristic impedance of a transmission line? The impedance of the line at any point The impedance of the line at the input end The impedance of the line at the output end The impedance that would make the line appear infinitely long Hint 72). What is the velocity factor of a transmission line? The ratio of the speed of light to the speed of electricity in the line The ratio of the effective propagation speed to the speed of light The ratio of the effective propagation speed to the speed of electricity in the line The ratio of the voltage to the current in the line Hint 73). What is the primary reason for using a transmission line? To reduce the amount of noise in a circuit To increase the bandwidth of a circuit To increase the power output of a circuit To prevent reflections from occurring in a circuit Hint 74). What is the purpose of a matching network in a transmission line? To ensure that the impedance of the line is the same at both ends To reduce the power loss in the line To increase the bandwidth of the line To reduce the amount of noise in the line Hint 75). What is the unit of measurement for characteristic impedance? Ohm Henry Farad Siemens Hint Transmission Distribution MCQ for Interviews 76). What is the formula for calculating the velocity factor of a transmission line? vf = c/2f vf = c/f vf = 2f/c vf = f/c Hint 77). What is the main difference between distribution and transmission lines? The voltage level carried by the lines The location of the lines The type of insulation used The material used for the lines Hint 78). What voltage level is typically used for distribution lines? Less than 10 kV Between 10 kV and 100 kV Between 100 kV and 500 kV Greater than 500 kV Hint 79). What is the formula for calculating the characteristic impedance of a transmission line? Z0 = sqrt(L/C) Z0 = L/C Z0 = sqrt(C/L) Z0 = C/L Hint 80). Which of the following is true about the Weibull distribution when the shape parameter is greater than 1? The distribution is symmetric The distribution is skewed to the left The distribution is skewed to the right The distribution is bimodal Hint 81). A 3-phase transmission line has a length of 300 km and a resistance of 0.2 Ω per phase. If the line is operating at a voltage of 220 kV and a current of 1000 A, what is the total power loss in the line? 8.4 MW 18.4 MW 28.4 MW 38.4 MW Hint 82). A distribution transformer has a rated power of 500 kVA, a rated voltage of 12 kV/240 V, and a rated efficiency of 98%. If the transformer is loaded to its full rated power, what is the primary current? 21.43 A 208.33 A 416.67 A 833.33 A Hint 83). A 3-phase distribution line has a length of 5 km and a resistance of 0.02 Ω per phase. If the line is operating at a voltage of 11 kV and a current of 400 A, what is the voltage drop in the line? 0.44 V 4.4 V 44 V 440 V Hint 84). A 3-phase transmission line has a length of 50 km and a capacitance of 0.02 μF per phase. If the line is operating at a voltage of 132 kV, what is the total reactive power in the line due to capacitance? 220 kVAr 440 kVAr 880 kVAr 1760 kVAr Hint 85). A 3-phase transmission line has a length of 100 km and a resistance of 0.2 Ω per phase. If the line is operating at a voltage of 400 kV and a power factor of 0.9, what is the minimum size of capacitor required at the receiving end to correct the power factor to unity? 22.2 Mvar 44.4 Mvar 88.8 Mva 177.6 Mvar Hint 86). What is the primary purpose of a transmission line in an electrical power system? To distribute electrical power to end-users To reduce the voltage level of electrical power To transmit electrical power over long distances with minimum losses To connect electrical power generation plants to the grid Hint 87). Which of the following is a type of distribution system commonly used in urban areas? adial distribution system Primary distribution system Secondary distribution system Ring main distribution system Hint 88). What is the primary function of a transformer in an electrical power system? To convert electrical energy into mechanical energy To convert high voltage to low voltage or vice versa To store electrical energy d. To regulate the frequency of electrical power Hint 89). What is the primary advantage of underground distribution systems over overhead distribution systems? Lower installation and maintenance costs Higher reliability and lower outage rates Better resistance to lightning strikes and other weather-related events Higher voltage levels and lower losses Hint 90). Which of the following is a common protective device used in electrical power systems to isolate a fault? Fuse Circuit breaker Transformer Capacitor Hint 91). What is the tripping mechanism of a circuit breaker? Magnetic Thermal Both A and B None of the above Hint 92). Which of the following is NOT a type of circuit breaker? hermal circuit breaker Magnetic circuit breaker Vacuum circuit breaker Hydraulic circuit breaker Hint 93). Which of the following is a common type of fault in electrical power systems? Open circuit Short circuit Overvoltage Undervoltage Hint 94). What type of fault is a circuit breaker designed to protect against? Open circuit Closed circuit Overload Resistance Hint 95). What is the main purpose of a circuit breaker? To conduct electricity To protect an electrical circuit from damage To measure electrical current To increase electrical voltage Hint 96). What is the most common cause of power outages on a distribution system? Lightning strikes Human error Equipment failure Hint 97). What is the main advantage of using underground cables for distribution? Lower cost Higher reliability Greater flexibility Easier maintenance Hint 98). What is the main disadvantage of using overhead lines for distribution? Higher cost Greater susceptibility to damage from weather Higher maintenance requirements Lower efficiency Hint 99). What is the most common method used to protect transmission lines from lightning strikes? Grounding Shielding Insulating Surge arresters Hint 100). What is the purpose of a transformer in a distribution system? To regulate voltage To regulate frequency To regulate current To provide power factor correction Hint Read more about Transmission Line Time's up
