Q#1: Multiplexing is:
(A) Combining multiple signals for transmission over a single medium
(B) Dividing a signal into multiple parts
(C) Amplifying signals
(D) Modulating signals
Answer: (A) Combining multiple signals for transmission over a single medium
Q#2: Demultiplexing is:
(A) Separating combined signals at the receiver
(B) Combining multiple signals
(C) Modulating signals
(D) Sampling
Answer: (A) Separating combined signals at the receiver
Q#3: Frequency Division Multiplexing (FDM) works by:
(A) Assigning each signal a different frequency band
(B) Assigning each signal a different time slot
(C) Changing signal amplitude
(D) Modulating phase
Answer: (A) Assigning each signal a different frequency band
Q#4: Time Division Multiplexing (TDM) works by:
(A) Assigning each signal a specific time slot
(B) Assigning each signal a frequency
(C) Modulating amplitude
(D) Changing phase
Answer: (A) Assigning each signal a specific time slot
Q#5: Synchronous TDM:
(A) Time slots are preassigned
(B) Time slots are dynamic
(C) Uses frequency bands
(D) None
Answer: (A) Time slots are preassigned
Q#6: Statistical TDM (STDM):
(A) Allocates time slots dynamically based on demand
(B) Preassigned slots
(C) Uses frequency bands
(D) None
Answer: (A) Allocates time slots dynamically based on demand
Q#7: Wavelength Division Multiplexing (WDM) is used in:
(A) Optical fiber
(B) Coaxial cable
(C) Twisted pair
(D) Wireless
Answer: (A) Optical fiber
Q#8: FDM advantage:
(A) Continuous transmission
(B) Simultaneous signal transmission
(C) High bandwidth efficiency
(D) All of the above
Answer: (D) All of the above
Q#9: FDM disadvantage:
(A) Requires guard bands
(B) Bandwidth wastage
(C) Crosstalk possible
(D) All of the above
Answer: (D) All of the above
Q#10: TDM advantage:
(A) Efficient bandwidth use
(B) No guard bands needed
(C) Can multiplex digital signals
(D) All of the above
Answer: (D) All of the above
Q#11: TDM disadvantage:
(A) Requires synchronization
(B) Wastes bandwidth if slots unused
(C) Both A and B
(D) None
Answer: (C) Both A and B
Q#12: Guard bands in FDM are used to:
(A) Prevent overlap between frequency channels
(B) Increase bandwidth
(C) Synchronize signals
(D) Multiplex signals
Answer: (A) Prevent overlap between frequency channels
Q#13: Digital TDM can be applied to:
(A) Digital signals
(B) Analog signals
(C) Both A and B
(D) None
Answer: (C) Both A and B
Q#14: FDM requires:
(A) Bandwidth greater than sum of signal bandwidths
(B) Equal time slots
(C) Guard intervals
(D) None
Answer: (A) Bandwidth greater than sum of signal bandwidths
Q#15: Multiplexing improves:
(A) Efficiency of media utilization
(B) Signal power
(C) Noise resistance
(D) Error detection
Answer: (A) Efficiency of media utilization
Q#16: Demultiplexer is used at:
(A) Receiver end
(B) Transmitter end
(C) Both
(D) None
Answer: (A) Receiver end
Q#17: Frequency band is:
(A) Range of frequencies assigned to a signal
(B) Time slot
(C) Amplitude range
(D) Phase range
Answer: (A) Range of frequencies assigned to a signal
Q#18: Optical TDM (OTDM) uses:
(A) Light pulses in different time slots
(B) Different wavelengths
(C) Frequency bands
(D) Phase shifts
Answer: (A) Light pulses in different time slots
Q#19: WDM advantage:
(A) High bandwidth utilization
(B) Long-distance transmission
(C) Multiple channels simultaneously
(D) All of the above
Answer: (D) All of the above
Q#20: Dense WDM (DWDM):
(A) Supports closely spaced wavelengths
(B) Uses wider spacing
(C) TDM-based
(D) None
Answer: (A) Supports closely spaced wavelengths
Q#21: Coarse WDM (CWDM):
(A) Uses wider wavelength spacing
(B) High density
(C) Only digital signals
(D) Only analog signals
Answer: (A) Uses wider wavelength spacing
Q#22: Frequency spectrum of a signal is:
(A) Range of frequencies contained in signal
(B) Time duration
(C) Amplitude range
(D) Phase range
Answer: (A) Range of frequencies contained in signal
Q#23: Multiplexing reduces:
(A) Number of required physical media
(B) Signal strength
(C) Bandwidth
(D) Power consumption
Answer: (A) Number of required physical media
Q#24: STDM disadvantage:
(A) Requires complex synchronization
(B) Idle time slots reduce efficiency
(C) Both A and B
(D) None
Answer: (C) Both A and B
Q#25: TDM vs FDM:
(A) TDM divides time, FDM divides frequency
(B) TDM divides frequency, FDM divides time
(C) Both divide amplitude
(D) None
Answer: (A) TDM divides time, FDM divides frequency
Q#26: Spread spectrum is used to:
(A) Spread signal over wider bandwidth than needed
(B) Reduce power
(C) Amplify signal
(D) None
Answer: (A) Spread signal over wider bandwidth than needed
Q#27: Frequency Hopping Spread Spectrum (FHSS):
(A) Transmits signal by rapidly changing carrier frequency
(B) Fixed frequency
(C) Uses amplitude variation
(D) None
Answer: (A) Transmits signal by rapidly changing carrier frequency
Q#28: Direct Sequence Spread Spectrum (DSSS):
(A) Multiplies data by pseudorandom code
(B) Frequency hopping
(C) Amplitude modulation
(D) None
Answer: (A) Multiplies data by pseudorandom code
Q#29: Spread spectrum advantage:
(A) Resistance to interference
(B) Security
(C) Multiple access capability
(D) All of the above
Answer: (D) All of the above
Q#30: Guard time in TDM prevents:
(A) Overlap of adjacent time slots
(B) Frequency interference
(C) Amplitude variation
(D) Phase mismatch
Answer: (A) Overlap of adjacent time slots
Q#31: Multiplexing in telephone networks:
(A) FDM analog signals
(B) TDM digital signals
(C) Both A and B
(D) None
Answer: (C) Both A and B
Q#32: Channel bandwidth in FDM must be:
(A) Greater than signal bandwidth + guard band
(B) Equal to signal bandwidth
(C) Less than signal bandwidth
(D) None
Answer: (A) Greater than signal bandwidth + guard band
Q#33: STDM efficiency increases when:
(A) All channels active
(B) Few channels active
(C) Idle time increases
(D) None
Answer: (A) All channels active
Q#34: FDM used in:
(A) Radio and TV broadcasting
(B) Telephone lines
(C) Optical fiber
(D) All of the above
Answer: (D) All of the above
Q#35: TDM used in:
(A) Digital telephony
(B) Satellite systems
(C) Both A and B
(D) None
Answer: (C) Both A and B
Q#36: Multiplexing reduces:
(A) Number of lines needed
(B) Bandwidth
(C) Amplitude
(D) Phase
Answer: (A) Number of lines needed
Q#37: Demultiplexer input:
(A) Combined signal
(B) Separate signals
(C) Single frequency
(D) None
Answer: (A) Combined signal
Q#38: Multiplexer output:
(A) Combined signal
(B) Separate signals
(C) Baseband only
(D) None
Answer: (A) Combined signal
Q#39: Optical WDM allows:
(A) Multiple wavelengths on single fiber
(B) Frequency hopping
(C) Time slot sharing
(D) None
Answer: (A) Multiple wavelengths on single fiber
Q#40: TDM vs STDM:
(A) TDM fixed slots, STDM dynamic allocation
(B) TDM dynamic, STDM fixed
(C) Both same
(D) None
Answer: (A) TDM fixed slots, STDM dynamic allocation
Q#41: FDM vs WDM:
(A) FDM uses electrical frequencies, WDM uses light wavelengths
(B) Both same
(C) FDM uses light
(D) None
Answer: (A) FDM uses electrical frequencies, WDM uses light wavelengths
Q#42: Spread spectrum reduces:
(A) Interference
(B) Noise
(C) Eavesdropping
(D) All of the above
Answer: (D) All of the above
Q#43: Multiplexing is essential for:
(A) Efficient media utilization
(B) Signal amplification
(C) Noise reduction only
(D) None
Answer: (A) Efficient media utilization
Q#44: Time slot duration in TDM:
(A) Fixed for synchronous TDM
(B) Variable for statistical TDM
(C) Both A and B
(D) None
Answer: (C) Both A and B
Q#45: Multiplexing reduces cost by:
(A) Reducing number of physical lines
(B) Reducing bandwidth
(C) Reducing signal power
(D) None
Answer: (A) Reducing number of physical lines
Q#46: FHSS frequency hop sequence must be:
(A) Known to both transmitter and receiver
(B) Random
(C) Only at transmitter
(D) None
Answer: (A) Known to both transmitter and receiver
Q#47: DSSS code is:
(A) Pseudorandom sequence
(B) Fixed frequency
(C) Amplitude modulated
(D) Phase modulated
Answer: (A) Pseudorandom sequence
Q#48: WDM wavelength spacing affects:
(A) Number of channels
(B) Crosstalk
(C) Bandwidth utilization
(D) All of the above
Answer: (D) All of the above
Q#49: Multiplexing applications:
(A) Telephone systems
(B) Cable TV
(C) Optical networks
(D) All of the above
Answer: (D) All of the above
Q#50: Efficient bandwidth utilization ensures:
(A) Maximum data transmission over minimum media
(B) Signal amplification
(C) Noise removal
(D) None
Answer: (A) Maximum data transmission over minimum media