Analog Communication Question & Answers April 23, 2021 By WatElectronics This article lists 100+ Analog Communication MCQs for engineering students. All the Analog Communication Questions & Answers given below includes solution and link wherever possible to the relevant topic. Communication means sharing information from one location to another. For example; mobile conversations, video lectures, etc. Samuel Morse invented Telegraph by using the morse code in 1837. The first revolution came in the world of communication after the telegraph and the telephone was invented by A.Graham bell in 1875. This was a wired communication that would be a sender or information source, input transducer, transmitter, channel, receiver, output transducer, and an information receiver. Examples of analog communication are amplitude modulation, frequency modulation, phase modulation, pulse amplitude, pulse width, and pulse position modulation. The benefit of having analog communication is, it is a simple type of communication technique, which uses less bandwidth, and multiplexing is easy, so we can just superimpose the signals in different frequencies of the carrier. 1). The square law modulator consists _______ Adder Non-linear device Bandpass filter All of the above Hint Read more about Band Pass Filter. 2). The amplitude modulation is the process in which amplitude of the carrier signal changes with respect to _____________ signal Modulating signal Carrier signal Suppressed carrier modulating signal None of the above Hint Read more about Amplitude Modulation. 3). The full-duplex is a _________ system Unidirectional communication Bidirectional communication Multidirectional communication None of the above Hint 4). Why the carrier signal doesn’t carry any signal? Frequency is constant Phase and amplitude constant Amplitude is Constant All of the above Hint 5). The standard form of PAM is _________ Pulse Amplitude Modulation Phase Amplitude Modulation Positive Amplitude Modulation None of the above Hint Read more about Pulse Amplitude Modulation. 6). The half-duplex is a _________ system Unidirectional communication Bidirectional communication Multidirectional communication None of the above Hint 7). The antenna height is equal to ______ h=λ/2 h=λ/8 h=λ/4 None of the above Hint 8). The advantages of the modulation are _______ High energy of carrier Noise can be reduced Multiplexing is possible All of the above Hint Read more about Modulation. 9). The simplex system is a _________ system Unidirectional communication Bidirectional communication Multidirectional communication None of the above Hint 10). How many types of electric communication systems are there? One Two Three Four Hint 11). Who invented first wireless radio wave over 1700 miles? Armstrong Oliver Lodge Goglielmo Marconi Samuel Morse Hint 12). _________ is the process in which amplitude of the carrier signal changes with respect to message or modulating signal Pulse modulation Angle modulation Amplitude modulation Frequency modulation Hint 13). The first wireless communication over short distance discovered by ________ Armstrong Oliver Lodge Goglielmo Marconi Samuel Morse Hint Read more about Wireless Communication. 14). The envelope detector is __________ Effective for detection of narrow band AM signal Simple Both a and b None of the above Hint 15). The number of bits conveyed or processed for unit time is called ________ Baud rate Bit rate ISI None of the above Hint 16). Who invented super heterodyne receiver? Armstrong Oliver Lodge Goglielmo Marconi Samuel Morse Hint 17). In ______ modulation the phase of the carrier signal is modulated by the message signal Pulse modulation Phase modulation Amplitude modulation Frequency modulation Hint 18). Who invented first frequency modulation demodulation? Armstrong Oliver Lodge Goglielmo Marconi Samuel Morse Hint 19). In ______ modulation the frequency of the carrier signal is modulated by the message signal Pulse modulation Phase modulation Amplitude modulation Frequency modulation Hint 20). Who did PCM encoding of speech signal for digital transmission? Alec Reeves Oliver Lodge Goglielmo Marconi Samuel Morse Hint 21). _________ noise is a static kind of noise which is generated due to electric disturbances Atmospheric noise Extraterrestrial noise Industrial noise Shot noise Hint 22). The industrial noise occurs in the range around ________ 300MHz-600MHz 1MHz-600MHz 200MHz-600MHz None of the above Hint 23). The area over which cosmic noise effects most is around ______ 10MHz-100MHz 20MHz-120MHz 20MHz-150MHz 30MHz-120MHz Hint 24). What are the external noise? Atmospheric noise Extraterrestrial noise Industrial noise All of the above Hint 25). The double side band suppressed carrier comes under _____ modulation Frequency modulation Analog pulse modulation Amplitude modulation Digital pulse modulation Hint 26). In baseband signal the audio frequency signal range is around ________ 0-20 KHz 10-20 KHz 5-10 KHz 0-20 MHz Hint 27). What are the noises comes under internal noise _____ Atmospheric noise, extraterrestrial noise Resistor, shot, and transient noise Industrial, miscellaneous noise None of the above Hint 28). In synchronous detector _______ errors are generated Phase type error Frequency type error Both a and b None of the above Hint 29). ___________ type of errors are generated in envelope detector Phase type error - Negative clipping Diagonal envelope Both b and c Hint 30). The complexity is _________ in synchronous detection High Low Medium Simple Hint Analog Communication Important MCQ’s 31). In base band signal the frequency range of amplitude modulation is around ________ 550KHz-1650KHz 500KHz-1600KHz 520 KHz-1620KHz 400 KHz-1650KHz Hint 32). In envelope detection the complexity is ____________ High Low Medium Simple Hint 33). The side band cancellation in filter method is done by using ______ Filter Phase shifter of 90 deg Phase shifter of 180 deg None of the above Hint 34). The frequency range of modulating signal in narrow band frequency modulation is between _________ 30 Hz - 15 KHz 15 Hz - 30 KHz 30 Hz - 3 KHz 3 Hz - 15 KHz Hint 35). When negative changes is happening to AF voltage the junction capacitance will actually _______ in varactor diode modulator Reduces Increases Remains same None of the above Hint 36). How much is the frequency band in GSM? 500 MHz 600 MHz 700 MHz 900 MHz Hint 37). In base band signal the video frequency signal range is around ________ 0-50MHz 0-55MHz 0-60MHz 10-55MHz Hint 38). In pass band signal, the frequency range of frequency modulation is around _________ 88 MHz-100MHz 88 MHz-110MHz 88 MHz-200MHz 88 MHz-101MHz Hint 39). The frequency band range of Code Division Multiplexing Access in pass band signal is around _______ 1500MHz 1600MHz 1700MHz 1800MHz Hint 40). In medium modulating index the modulation index is ________ Less than one One to ten Greater than ten Between 1 to 10 Hint 41). The side band cancellation in phase shift method is done by using ______ Selectivity Fidelity Sensitivity All of the above Hint 43). In super heterodyne receiver, at high frequency the ______ Bandwidth is low Signal processing should be done Signal transmission should be done Both b and c Hint 44). The maximum deviation in narrow band frequency modulation is around _________ 5 MHz 5 KHz 7 MHz 9 MHz Hint 45). When several signals are multiplexed in a frequency domain then the modulation is called ________ Frequency Division Multiplexing Time Division Multiplexing Code Division Multiplexing Space Division Multiplexing Hint 46). When figure of merit is less than one, the output of signal to noise ratio is _______ the input of signal to noise ratio Less than input SNR Greater than input SNR Greater than or equal to input SNR Less than or equal to SNR input Hint 47). The levels in differential pulse code modulation are ______ More Depends on number of bits Less None of the above Hint 48). _______ quantizer minimizes the quantization error Uniform quantizer Non-Uniform quantizer LLOYD-Max quantizer None of the above Hint 49). The quantization error can be defined as _______ q=Q(m)+m q=Q(m)-m q=Q(m)/m None of the above Hint 50). What are the advantages of the angle modulation over amplitude modulation? Noise reduction Improved system fidelity Efficient use of power All of the above Hint 51). What are the applications of Angle modulation? Radio broadcasting TV sound transmission Cellular radio All of the above Hint 52). How many categories does the modulation index have? One Two Three Four Hint 53). In lower modulating index the modulation index is ________ Less than one One to ten Greater than ten None of the above Hint 54). In a higher modulating index the modulation index is ________ Less than one One to ten Greater than ten None of the above Hint 55). When several signals are multiplexed in a time domain then the modulation is called ________ Frequency Division Multiplexing Time Division Multiplexing Code Division Multiplexing Space Division Multiplexing Hint 56). Which noise comes under internal noise? Resistor noise Transient noise Shot noise All of the above Hint 57). The SNR in delta modulation is ______ Fair Poor Good None of the above Hint 58). The quantization is a many to one mapping, in which all sample values in a particular interval are mapped to a __________ Quantization level Uniform quantization Non-uniform quantization None of the above Hint 59). In _________ modulation, frequency or phase of carrier signal changes with respect to modulating signal Frequency Modulation Amplitude Modulation Delta Modulation Angle modulation Hint 60). The maximum deviation in wideband frequency modulation is around _________ 75 MHz 75 kHz 70 MHz 90 MHz Hint Analog Communication MCQ’s for Interviews 61). The frequency range of modulating signal in wideband frequency modulation is between _________ 30 Hz - 15 kHz 15 Hz - 30 kHz 30 Hz - 10 kHz 3 Hz - 15 kHz Hint 62). The SSB frequency range is __________ in filter method Frequency is high Frequency is low Applicable for any frequency None of the above Hint 63). The bandwidth for transmission in pulse code modulation is __________ Higher than the DPCM Lower than the DPCM Equal to DPCM None of the above Hint 64). The formula of amplifier is given by ___________ F+1/F 2F-1/F F-1/F None of the above Hint Read more about Amplifier. 65). When the figure of merit is greater than one, the output of a signal to noise ratio is _______ the input of a signal to noise ratio Less than input SNR Greater than input SNR Greater than or equal to input SNR Less than or equal to SNR input Hint 66)________ is a differential modulation Frequency Modulation Amplitude Modulation Delta Modulation None of the above Hint Read more about Delta Modulation. 67). The additive white Gaussian noise _______ Requires infinite power Requires finite power Doesn’t require power None of the above Hint 68). The thermal noise _______ Requires infinite power Requires finite power Doesn’t require power None of the above Hint 69). The number of bits in DPCM is _______ Greater than PCM Less than PCM Equal to PCM None of the above Hint 70). The levels in PCM are ______ More Depends on the number of bits Less None of the above Hint 71). In which case the step size is not fixed? Pulse Code Modulation Delta Modulation Differential Pulse Code Modulation Adaptive Delta Modulation Hint Read more about Adaptive Delta Modulation. 72). The bandwidth for transmission in differential pulse code modulation is __________ Higher than the PCM Lower than the PCM Equal to PCM None of the above Hint 73). When positive changes are happening to AF voltage the junction capacitance will actually _______ in varactor diode modulator Reduces Increases Remains the same None of the above Hint 74). The quantization error in PCM is ________ Depends upon the levels Doesn’t depend upon the levels Depends upon the step size None of the above Hint 75). The SNR in PCM is ______ Fair Poor Good None of the above Hint 76). In a uniform quantizer with an even number of quantization levels, the quantizer characteristics arise from __________ –Δ to +Δ –Δ/2 to +Δ/2 –Δ/4 to +Δ/4 None of the above Hint 77). The SNR in adaptive delta modulation is ______ Fair Poor Good Better than DM Hint 78). The quantization error in DPCM is ________ Quantization is present Quantization is not present Quantization is present but less than PCM None of the above Hint 79). Analog communication uses _______ types of signals. Continuous Discontinuous Both a and b None of the above Hint 80). In which technique data is transmitted using continuous signals? Analog communication Digital communication Both a and b None of the above Hint 81). An analog signal is _______ signal continuous in both time and amplitude. Variable signal Invariable signal Both a and b None of the above Hint 82). In which technique physical transfer of data over a point to point or point to multi-point transmission medium is done? Analog communication Digital communication Both a and b None of the above Hint 83). Which of the following are the examples of analog communication technology? Photocopiers Audio tapes Emails Both a and b Hint 84). Which of the following are the examples of digital communication technology? Photocopiers Audio tapes Emails Both a and b Hint 85). Digital communication is represented in ______ form. 0’s 1’s Both a and b Option an alone Hint 86). An analog signal is represented in ______ form. Time domain Frequency domain Both a and b None of the above Hint 87). What is the serious issue in analog communication compared to digital communication? Has noise Free from noise Has maximum amplitude Has the maximum frequency Hint 88). In analog communication electronic noise and disturbance is introduced into transmission channel results in _______. Reduces signal to noise ratio Increases signal to noise ratio Improves signals amplitude None of the above Hint 89). Analog communication contains _______ number of components. 4 5 6 3 Hint 90). What is the function of an information source? Information is generated Information is sent Information is received Information is read Hint Analog Communication Important MCQ’s with Hints 91). Messages generated in an input source block of analog communication can be in which form? Words, group of words Symbols Signals All the above Hint 92). What is the function of a transducer? Converts energy from one form to another Converts signals Converts domains Hint Read more about Transducer. 93). Radio broadcasting converts ______ into ______ using transducer. Nonelectrical, electrical Electrical, nonelectrical Electrical, electrical Nonelectrical, nonelectrical Hint 94). What is the function of the transmitter? Transmits signal to the receiver Accepts signal from the transducer Accepts input from information source Transmits signal over a channel. Hint 95). Which technique is used in the transmitter? Modulation Demodulation Both a and b None of the above Hint 96). What is the functionality of a channel? It transmits a message from the transmitter to the receiver It listens to message It holds a message All the above Hint 97). How many types of channels are used in analog communication components? Two One Three Four Hint 98). Which of the following channels are used in analog communication? Point to point Broadcast channel Narrowband channel Wideband channel Both a and b Hint 99). Which of the following are examples of point to point channel? Wire lines Microwave links Optical fibers All the above Hint 100). What is the functionality of the broadcast channel? It handles several incoming messages from a transmitter It holds single information It listens to channel None of the above Hint 101). What is the functionality of the receiver? It produces an electric message from the received signal in a distorted form It receives the input from the channel Both a and b None of the above Hint 102). Which technique is performed in the receiver? Modulation Demodulation Both a and b None of the above Hint 103). What is the functionality of the destination? Converts electrical signal into the original input Converts original input to electrical form Receives input from the receiver It is the final stage of analog communication Option a, b ,d are considered Hint 104). A periodic signal is of _______ pattern with respect to time. Repetitive Nonrepetitive Alternative None of the above Hint 105). An aperiodic signal is of _______ pattern with to time. Repetitive Nonrepetitive Alternative None of the above Hint 106). What happens to the message if the message signal characteristic is changed? Message gets altered Message remains same Message is not transmitted None of the above Hint 107). A _______ frequency signal can carry a message over a long distance. Short frequency High frequency Low frequency Big frequency Hint 108). A high frequency signal is also called as ______ signal. Carrier signal UV signal Radio signal None of the above Hint 109). In digital communication does antenna size reduces in modulation technique? Yes No Maybe Hint 110). What are the types of signals used in the modulation? Carrier signal Modulated signal Modulating or message signal All the above Hint 111). Which of the following modulation technique is used for analog modulation? Continuous wave modulation Pulse modulation Both a and b None of the above Hint 112). Which of the following comes under continuous wave modulation? Amplitude modulation Angle modulation Analog modulation Digital modulation Both a and b Hint 113). Which of the following is angle modulation? Pulse amplitude modulation Pulse width modulation Phase modulation Frequency modulation Both c and d Hint 114). Which of the following is pulse modulation? Analog modulation Frequency modulation Digital modulation Both a and c Hint 115). Which of the following is an analog modulation? Pulse type amplitude modulation PAM Pulse type width modulation PWM Pulse type position modulation PPM All the above Hint 116). Which of the following is a digital modulation? Pulse code modulation Delta modulation Frequency modulation Both a and b Hint 117). How many types of modulators are present in double side band suppressed carrier? One Two Three Four Hint 118). What are the components in a balanced modulator? AM type modulator two in number A Local oscillator Summer All the above Hint 119). A ring modulator contains how many diodes? 2 3 4 5 Hint Read more about Diodes. 120). DSBSC modulators are also called as ________. Product type modulators Adder modulator Summer modulator None of the above Hint 121). Pulse modulation is _______ sequence pf rectangular pulse. Periodic sequence Aperiodic sequence Nonrepetitive sequence Both b and c Hint 122). Which of the following statement is true for pulse amplitude modulation PAM? The pulse amplitude is varied with respect to instantaneous values of baseband modulating signal The pulse width is varied with respect to instantaneous values of baseband modulating signal The pulse position is varied with respect to instantaneous values of baseband modulating signal The pulse duration is varied with respect to instantaneous values of baseband modulating signal Hint 123). Which of the following statement is true for pulse width modulation? The pulse amplitude is varied with respect to instantaneous values of baseband modulating signal The pulse width is varied with respect to instantaneous values of baseband modulating signal The pulse position is varied with respect to instantaneous values of baseband modulating signal The pulse duration is varied with respect to instantaneous values of baseband modulating signal Hint 124). Which of the following statement is true for pulse position modulation? The pulse amplitude is varied with respect to instantaneous values of baseband modulating signal The pulse width is varied with respect to instantaneous values of baseband modulating signal The pulse position is varied with respect to instantaneous values of baseband modulating signal The pulse duration is varied with respect to instantaneous values of baseband modulating signal Hint 125). Message signal in the time domain is represented as ________. m(t)= Amcos(2πfmt) M (t) = A cos (2π fm t) M(t) = A cos (2π f t) m (t) = Am cos (2π f t) Hint 126). Carrier signal in time domain is represented as ________. c (t) = Ac cos ( 2π fc t) c (t) = Ac cos ( 2π t) c (t) = Ac cos ( π fc t) C (t) = Ac cos ( 2π fc t) Hint 127). What is the formula for modulation index “µ” when amplitudes of modulating signal “Am” and carrier signal “Ac” is known? µ = Am / Ac µ = Ac / Am µ = Am µ = Ac Hint 128). What is the condition for perfect modulation? µ = 1 µ = 0 µ < 1 µ > 1 Hint 129). How many types of demodulators are present in a DSBSC wave? One Two Three Four Hint 130). If the maximum frequency is subtracted from lower frequency it is called ________. Amplitude Bandwidth Frequency Time period Hint 131). What is the bandwidth of AM wave? BW = 2fm BW = fm BW = 2 BW = 3 Hint 132). Which type of modulators are used in AM wave generation? Square law modulator Switching modulator Triangular modulator Both a and b Hint 133). Which of the following are the components of square law modulator? Summer Square law device Bandpass filter All the above Hint 134). Which of the following are the components of the switching modulator? Summer Switching diode Bandpass filter All the above Hint 135). The process of extracting the original message from the signal is called _______. Modulation Demodulation Encryption Decryption Hint 136). Demodulation is done at ______ side. Transmitter Receiver Channel Both a and b Hint 137). What is the functionality of the envelope detector? It detects AM wave with high frequency It detects FM wave high frequency It detects PM wave high frequency None of the above Hint Time is Up! Time's up
