LiFi Question and AnswersMarch 9, 2021 By admin This article lists 50+ LiFi Technology MCQs for engineering students. All the LiFi Technology 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 their fundamentals on LiFi Technology.Current digital communication is entirely based on the internet, where all smart devices like laptops, computers, watches, mobile phones, etc are connected to the internet via a physical medium like routers, fire sticks, etc. A smart 5th generation technology which is an advanced version of Wi-Fi is Li-Fi, Light Fidelity technology. LiFi technology generally uses 6 modulation schemes, namely on-off keying – OOK, variable pulse positioning modulation – VPPM, color shift keying –CSK, subcarrier inverse PPM – SCIPPM, Frequency shift keying – FSK, SIM – OFDM – subcarrier index modulation OFDM. Some of the advantages of LiFi technology are it is a cost-efficient process, simple and fast in operation. LiFi technology is commonly applied in military communication, corporates offices, hospitals, etc. 1). LiFi stands for?Light FidelityLife FidelityLean FidelityNone of the aboveHintLiFi stands for Light Fidelity. 2). LiFi technology was proposed by___?RichardEdinburghDennisCharlesHintLiFi technology was proposed by German Physicist Edinburgh in 2011. 3). LiFi technology connects to the Internet using _____ sourcePluginVoltage sourceLightFirewallHintLiFi technology connects to the Internet using light resources. 4). Which of the following are the advantages of LiFi technology?Cost efficientSimpleFasterAll the aboveHintThe advantages of LiFi technology are it is a cost-efficient process, simple and fast in operation. 5). Does LiFi technology requires any physical medium like a router to access the Internet?YesNoMaybeDepends on the situationHintNo, LiFi technology does not require any physical medium like a router to access the Internet. 6). LiFi technology is a _____ Directional wireless systemBi-directionalUnidirectionalMulti-directionalNone of the aboveHintLiFi technology is a Bi-directional wireless system that transmits data in electrical form using LED. 7). Which of the following are the basic components of LiFi technology?Light sourceElectronic chipWifiAll the aboveHintLiFi technology transmits Internet (WiFi) signals using a light source and a chip. 8). LiFi technology improves which of the following factor of wifiSpeedBandwidthNoiseBoth a and bHintLiFi technology improves the speed and bandwidth factor of wifi. 9). If a number of users using LiFi technology at a time it _____ the performanceImprovesDegradesMaintenance stableBoth a and bHintIf a number of users using LiFi technology at a time it degrades the performance. 10). What is the frequency of LiFi technology?200,000GHz100, 000 GHz300,000 GHz20000MHzHintThe frequency of LiFi technology of 200,000GHz. 11). Which of the following is the application of LiFi technology?Home AppliancesHospitalsAirportsAll the aboveHintThe Applications of LiFi technology are home appliances, hospitals, airports. 12). Which of the following is the speed of WiFi technology?11 to 300 Mbits/sec10 to 300 Mbits/sec11 to 100 Mbits/sec11 to 1300 Mbits/secHintThe speed of WiFi technology is 11 to 300 Mbits/sec. 13). VLC stands forVisible light communicationVariable light communicationVisibility laser communicationAny of the aboveHintVLC stands for Visible light communication. 14) LiFi has _____ many times greater bandwidth than radio spectrum10,000100101000HintLiFi has.10, 000. many times greater bandwidth than radio spectrum. 15). Is LiFi technology is more reliable than WiFi?YesNoMaybeNone of the aboveHintYes, LiFi technology is more reliable than WiFi. 16). LiFi is a _____ Networking TechnologyWireless opticalWiredWired transmissionLANHintLiFi is a wireless optical networking technology. 17). LiFi is _____for high density data coverageStaticDynamicIdealInfiniteHintLiFi is ideal for high-density data coverage. 18). LED stands forLight emitting diodeLithium emitted diodeLight emission diodeLight emitting deviceHintLED stands for a light-emitting diode. 19). The spectrum used in LiFi10,000 times greater than WiFi100 times greater than WiFi spectrumNarrow spectrumBroad spectrumHintThe spectrum used in LiFi is 10,000 times greater than WiFi. 20). Data density in WiFi is _____ than LiFiHighLowMediumZeroHintData density in WiFi is low than LiFi.LiFi Technologies Interview Questions and Answers 21). The latency of LiFi technology is _____LowHighOrder of microsecondsOrder of millisecondsHintThe latency of LiFi technology is in order of microseconds. 22). Obstacle interference is _____ in Li-Fi technology than WiFi technologyHighLowMedium0HintObstacle interference is high in Li-Fi technology than WiFi technology. 23). The process that uses a rapid pulse of light to transmit information wirelessly is technically referred to as _____VLCLEDDiodeTorchHintThe process that uses a rapid pulse of light to transmit information wirelessly is technically referred to as VLC - visible light communication. 24). Li-Fi technology works on the principle of _____VLCLEDDiodeTorchHintLi-Fi technology works on the principle of VLC. 25). VLC - visible light communication is based on which electronic component?LEDDiodeTorchNone of the aboveHintVLC - visible light communication is based on LED, where it acts as a switch in transmitting data digitally. That is if a switch is closed then it is represented digitally as logic “1” which means data is being transmitted and if a switch is opened then it is represented digitally as logic “0” which means data is not being transmitted. 26). How many modulation schemes are used in LiFi technology?3456HintLiFi technology uses 6 modulation schemes, namely on-off keying – OOK, variable pulse positioning modulation – VPPM, color shift keying –CSK, subcarrier inverse PPM – SCIPPM, Frequency shift keying – FSK, SIM – OFDM – subcarrier index modulation OFDM. Read more about Modulation 27). On-off keying – OOK modulation technique uses _____ coding techniqueManchester codingHash KeyMD5All the aboveHintOn-off keying – OOK modulation technique uses Manchester coding technique, which states that time period of both positive and negative pulses are equal. 28). In on-off keying – OOK modulation technique if the bit rate is high _____ coding is usedManchester codingRun length limitedMD5All the aboveHintIn on-off keying – OOK modulation technique if the bit rate is high run length limited coding is used. This coding provides an efficient spectrum. 29). Standard VLC specifies VLC consist of _____ number of communication types2345HintStandard VLC consists of 3 number of communication types namely – mobile to mobile M2M, fixed to mobile (F2M), and infrastructure to mobile (I2M). 30). VLC mainly focuses on _____ range of communication for traffic intelligence system at low speed and short rangeLargeMediumSmallVery largeHintVLC mainly focuses on a medium range of communication for traffic intelligence systems at low speed and short-range. 32). LiFi communication is defined in _____ and _____ layers for VLC/LiFiPhysical layer, medium access layer (MAC)Medium access layer (MAC), Data layerData layer, physical layerPhysical layer, transport layerHintLiFi communication is defined in physical layer and medium access layer (MAC) layers for VLC/LiFi. 33). MAC layer has _____ number of multi-access technologies2346HintMAC layer has 3 number of multi-access technologies namely peer-to-peer technology, star configuration technology, and broadcast mode. 31). What is the range of data rates supported by various modulation schemas?100 kbps to 100 Mbps10 kbps to 100 Mbps100 bps to 100 Mbps100 kbps to 100 GbpsHintThe range of data rates supported by various modulation schemas is 100 kbps to 100 Mbps. 34). MAC layer addresses _____ Layer issues such as addressing, collision avoidanceData layerPhysical layerTransport layerNone of the aboveHintMAC layer addresses physical Layer issues such as addressing, collision avoidance. 35). The physical layer in MAC is divided into _____ number of phases2345HintThe physical layer in MAC is divided into 3 number of phases, namely phase I, II, III. 36). PPM or VPPM modulation scheme encodes the data using _____ parameter of pulse in a time periodPositionLengthDistancePhaseHintPPM or VPPM modulation scheme encodes the data using position parameter of pulse in a time period. 37). Which type of modulation scheme is used when RGB type LED illumination system is used?Color shift keyingVPPMOOKFSKHintColor shift keying modulation scheme is used when RGB type LED illumination system is used. 38). RGB in RGB -LED stands for?Red, green, blueRed, grey, blueRead, gate, blueNone of the aboveHintRGB in RGB - LED stands for red, green, blue color lights. Read more about RGB 39). RGB-CSK modulation scheme _____ the complexity of trans receiverIncreaseDecreasesMaintains the sameZeroHintRGB-CSK modulation scheme increases the complexity of the trans-receiver. 40). SCIPPM modulation scheme is further classified into how many partsOneTwoThreeFourHintThe SCIPPM modulation scheme is further classified into two many parts, namely sub-carrier, and DC. 41). What is the purpose of DC in SCIPPM modulation?Used for lighting purposeTransmission purposeReceiving purposeStorage purposeHintThe purpose of DC in SCIPPM modulation is for lighting purposes. 42). Data in FSK modulation is represented by _____ of the carrier signalVarying frequencyVarying messageVarying amplitudeNone of the aboveHintData in FSK modulation is represented by varying the frequency of the carrier signal. 43). Data in digital form is represented as _____0’s1’sASCIIBoth a and bHintData in digital form is represented in 0’s and 1’s. 44). Which of the following are the components used in LiFi smart classes?Transmission sourceReceiving elementServerAll the aboveHintThe components used in LiFi smart classes are transmission source, receiving element, server, interactive bond, computer, projector. 45). Which of the following are the limitation of Li/Fi technology?Does not pass through objectsNetwork coverage is lessLow reliabilityAll the aboveHintThe limitation of Li/Fi technology is it provides less reliability, less network coverage, it doesn't pass through obstacles, high installation cost.Li-Fi Technology Quiz Questions and Answers 46). LiFi technology is _____ generation technology2G3G3G5GHintLiFi technology is a 5th Generation technology. 47). Which of the following factors are considered while designing LiFi?LightLOS- Line of sightLEDAll the aboveHintThe factors considered while designing LiFi are light, LED, LOS- Line of sight, photodetector data that is received. 48). LOS stands forLine of sightLose of sightLose of signalLine of sightHintLOS stands for Line of sight. 49). Is LiFi technology better than WiFi?YesNoBoth a and bDepends on factorsHintYes, LiFi technology better than WiFi. Since it can download data faster than wifi technology. 50). WiFi stands forWireless FidelityWired FidelityWide FidelityNone of the aboveHintWiFi stands for Wireless Fidelity. Read more about WiFi Technology 51). The data in LIFI is transmitted using the _____Infrared wavesUltraviolet wavesRadio wavesNone of the aboveHintThe data in LIFI is transmitted using radio waves. 52). The speed of the LIFI technology is up to ______20Gbps30Gbps10GbpsNone of the aboveHintThe speed of the LIFI technology is up to 10Gbps. 53). The maximum speed supported by the standard IEEE 802.11ac is _______20Gbps1.3Gbps10GbpsNone of the aboveHintThe maximum speed supported by the standard IEEE 802.11ac is up to 1.3Gbps that is under the 5GHz band which is almost 100 times lesser compared to the speed which is supported by LIFI. 54). The maximum speed supported by the standard IEEE 802.11ad is ______20Gbps7Gbps10GbpsNone of the aboveHintThe maximum speed supported by the standard IEEE 802.11ad is 7Gbps which is under the 60GHz band. 55). The bandwidth of the radio waves is ______200GHz100GHz300GHzNone of the aboveHintThe bandwidth of the radio waves is around 300GHz. 56). The bandwidth of the visible spectrum is ______200GHz100GHz300THzNone of the aboveHintThe bandwidth of the visible spectrum is around 300THz which is almost a thousand times more compared to the bandwidth of the radio waves. 57). The range of LIFI is _____11Mbps12 Mbps20 MbpsNone of the aboveHintThe range of LIFI depends on the intensity of the LED. 58). In security aspire the LIFI is _____Low secureHighly secureMedium secureNone of the aboveHintIn security aspire the LIFI is highly secure. 59). The LIFI uses standard of ______IEEE 802.15IEEE 801.15IEEE 804.15None of the aboveHintThe LIFI uses IEEE 802.15 standard. 60). The development of LIFI technology started in _______199020002011None of the aboveHintThe development of LIFI technology started in the year 2011. Time is Up!