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WorksheetsCommunication Systems Quiz
Total questions: 131
Worksheet time: 1hrs 8mins
What is communication in its simplest form?
Exchanging recipes between chefs
Exchanging messages between sender and receiver
Exchanging goods in a marketplace
Exchanging passwords between computers
What types of conversations can communication involve?
Only technical instructions
Only mathematical discussions
Plain conversations about thoughts, ideas, and feelings
Only legal negotiations
What are the two forms of communication mentioned?
Written and printed communication
Digital and analog communication
Verbal and nonverbal communication
Social and cultural communication
What does "communication systems" refer to in electronics?
Cooking with multiple utensils
Transportation networks
Communication using a transmitter, channel, and receiver
Banking transactions
What is the message called in communication systems?
A transaction
Information or intelligence signal
A contract
A report
What is the first step in sending a message?
Deliver it directly by hand
Convert it into an electronic form
Encrypt it using a password
Print it on paper
What device converts sound to an electronic audio signal?
Speaker
Microphone
Antenna
Amplifier
How does a camera function in communication systems?
It stores digital codes
It converts typed words to images
It converts light information to a video signal
It amplifies sound
What is used to convert typed messages in computer systems?
Morse code
Binary codes
Braille symbols
Phonetic alphabet
What do transducers do in communication systems?
Store energy
Convert physical characteristics into electronic signals
Transmit signals through space
Encrypt digital data
What is a communication channel?
The subject of discussion
The medium for sending electronic signals
The antenna at the transmitter
The conversation itself
What is an electrical conductor?
A resistor
A material that conducts electricity
A plastic coating
A transformer
What do optical media do in communication systems?
Store magnetic signals
Carry messages on a light wave
Convert images to sound
Transfer heat energy
What is radio in terms of communication channels?
Wired communication between offices
Wireless communication from point to point
Musical broadcasting only
Data stored on tapes
How does passive sonar work?
By bouncing radar waves off objects
By converting light to sound
It listens for underwater sounds with hydrophones
By transmitting strong acoustic pulses
What is the role of a receiver in communication systems?
To delete unwanted signals
To accept and translate transmitted messages
To store large amounts of data
To generate waveforms
What do amplifiers do in a receiver?
Block unwanted frequencies
Produce an increased version of the input signal
Compress the waveform
Convert sound into images
What is the function of oscillators in a receiver?
Amplify weak signals
Store audio recordings
Produce a continuous, repeated waveform
Measure resistance
What do mixers do in communication systems?
Filter out noise
Combine two or more electronic signals
Convert signals to binary
Store energy in a capacitor
What are tuned circuits in a receiver?
Circuits that filter out all signals
Circuits responsive to a specific frequency
Circuits that only work with digital signals
Circuits that block light waves
What is the purpose of filters in a receiver?
Amplify all frequencies equally
Block all incoming signals
Amplify specific frequencies while attenuating others
Convert signals into binary code
What are the five blocks in the block diagram of communication systems?
Source, Processor, Storage, Output, Feedback
Input, Encoder, Decoder, Output, Noise
Information Source, Transmitter, Channel, Receiver, Destination
Transmitter, Antenna, Satellite, Receiver, Speaker
What is the process flow in a communication system?
Destination → Receiver → Transmitter → Source
Channel → Transmitter → Source → Receiver → Destination
Starts with the information source → transmitter → channel → receiver → destination
Receiver → Source → Transmitter → Channel
What are the types of communication channels mentioned?
Mechanical, electrical, digital
Electrical conductors, optical media, free space
Coded, analog, encrypted
Verbal, nonverbal, written
What is the function of active sonar?
It records music underwater
Use echo-reflecting technique to detect objects
It amplifies low-frequency sounds
It filters ocean noise
How are electronic communications categorized?
By power and frequency
By one-way or two-way transmissions
By analog and optical media
By speed of processing
What are the two types of signals in electronic communications?
Light and sound
Verbal and nonverbal
Analog and digital signals
Primary and secondary
What is simplex communication?
Two-way communication without interruptions
One-way communication where the receiver cannot respond
Communication through satellite only
Communication with feedback loops
What are the characteristics of simplex communication?
Both sides can talk simultaneously
One-way transmission; receiver cannot send information back; examples: TV broadcasting, remote control
Communication requires encryption
Messages are stored and retrieved later
What type of communication is a simplex?
It can be a downlink or uplink
It is always two-way
It requires both parties to respond alternately
It uses only optical media
In a simplex downlink, what does the satellite do?
Transmits television programming to the home antenna
Receives commands from a remote
Sends audio signals only
Provides two-way communication
Why is the TV considered a simplex downlink?
It can respond to commands
It does not talk back
It only transmits audio
It communicates via binary codes
What is used for the satellite to receive programming material from a ground-based TV station?
Simplex uplink
Duplex downlink
Binary code system
Amplified broadcast
How are the up and down links characterized in simplex communication?
They are mixed into one path
They are separated connections
They are simultaneous
They are non-existent
What type of link is used to control a drone?
A simple control link
An optical uplink
A binary code uplink
A sonar frequency link
What occurs when the drone’s camera transmits video back to the operator?
Simplex downlink
Duplex transmission occurs
Passive communication
Coded uplink
What are the types of duplex communication?
Mixed and direct
Full duplex (simultaneous two-way), Half duplex (two-way but not simultaneous)
Analog and digital duplex
Primary and secondary duplex
What can devices do in full duplex communication?
Send and receive signals simultaneously
Only receive signals
Only transmit signals
Store data for later
How does full duplex differ from half-duplex communication?
Full duplex is one-way
Full duplex allows simultaneous communication
Half duplex is faster
Half duplex requires optical links
What type of communication is half-duplex
What type of communication is half-duplex?
Two-way communication with alternating direction
Two-way simultaneous communication
One-way communication only
Encrypted communication
How do communicating parties operate in half-duplex communication?
Both speak at the same time
They take turns transmitting and receiving
They cannot respond
They store data before sending
Which devices commonly use half-duplex communication?
Smartphones
Military radios and walkie-talkies
Television sets
Fiber optic cables
What is an analog signal?
A digital code
A continuously varying voltage or current
A stored message
A binary string
What is a sine wave tone?
A type of digital signal
A type of analog signal
A binary code
A constant DC voltage
Which type of signal includes voice?
Digital signal
Analog signal
Binary code
Morse code
What type of signal is a TV signal classified as?
Analog signal
Digital signal only
Binary-coded signal
Morse telegraph
What does a signal represent in electronic communication?
A random waveform
Noise only
Information or data carried from source to destination
A static interference
What is the purpose of electronic circuits in signal processing?
To store electricity
To manipulate signals for desired results
To generate noise
To block all signals
What does gain mean in the context of signals?
Amplification of a signal's amplitude
Loss of a signal
Storage of a message
Conversion into binary
How is gain represented in circuits?
By the letter A and is unitless
By the letter G and in volts
By the letter P and in watts
By the letter C and in ohms
How is voltage gain (Av) calculated?
Av = Vin / Vout
Av = Vout / Vin
Av = Pin / Pout
Av = Pout / Pin
If Vin is 140 μV and Vout is 65 mV, what is the voltage gain (Av)?
Av = 10
Av = 464.29
Av = 1000
Av = 200
What does the ratio obtained from output over input indicate?
The loss in transmission
The data encoding rate
How much larger the output is than the input
The number of binary codes
How do you find Vout if Vin is 0.7 V and Av is 230?
Vout = 50 V
Vout = 161 V
Vout = 100 V
Vout = 230 V
What is the formula for power gain (Ap)?
Ap = Vin / Vout
Ap = Pout / Pin
Ap = Vout / Vin
Ap = Pin / Pout
How is total gain (AT) calculated in cascaded circuits?
By multiplying individual circuit gains
By subtracting gains
By dividing outputs
By averaging voltages
If three amplifiers have gains of 5, 3, and 4, what is the total gain (AT)?
AT = 12
AT = 60
AT = 20
AT = 7
What does attenuation refer to in a circuit?
Increase of signal amplitude
Loss of signal amplitude
Storing power in circuits
Filtering frequencies
When does a circuit have attenuation?
If output is higher than input amplitude
If output is lower than input amplitude
If gain is above 1
If there is no signal
How is attenuation represented in formulas?
By the letter A
By the letter G
By the letter P
By the letter R
What is the output voltage if Vin is 10 V and A is 0.3333?
Vout = 30 V
Vout = 5 V
Vout = 3.33 V
Vout = 0.33 V
How is total attenuation (AT) calculated in cascaded circuits?
By multiplying individual attenuations
By dividing individual gains
By adding power inputs
By subtracting voltages
If individual attenuations are 0.2, 0.9, and 0.06, what is the total attenuation (AT)?
AT = 0.12
AT = 0.01
AT = 0.0108
AT = 0.2
What is the output voltage if input is 3 V and AT is 0.0108?
Vout = 0.0324 V
Vout = 3.24 V
Vout = 0.3 V
Vout = 0.108 V
How can loss in a circuit be compensated?
By using more resistors
By blocking frequencies
By adding a stage of amplification
By lowering input voltage
What is the formula for total gain or attenuation in a circuit?
AT = A1 + A2
AT = A1 × A2
AT = A1 – A2
AT = A1 ÷ A2
What does a total gain of 1 indicate?
Complete signal loss
It offsets the original attenuation
Signal distortion
Infinite amplification
What unit is used to express gain or attenuation?
Hertz
Ohms
Decibels (dB)
Volts
Why are decibels used in measuring gain or attenuation?
To encrypt messages
To simplify large gain or attenuation figures
To reduce circuit noise
To change frequencies
What is the formula for voltage gain in decibels?
dB = 10 log(Vout / Vin)
dB = 20 log(Vout / Vin)
dB = 5 log(Vout / Vin)
dB = 100 log(Vout / Vin)
What is the formula for power gain in decibels?
dB = 10 log(Pout / Pin)
dB = 20 log(Pout / Pin)
dB = 5 log(Pout / Pin)
dB = 100 log(Pout / Pin)
If an amplifier has an input of 4 mV and an output of 7 V, what is the gain in decibels?
54 dB
64.86 dB
70 dB
80 dB
If a filter has a power input of 60 mW and an output of 3 mW, what is the gain in decibels?
-10 dB
-13.01 dB
+13.01 dB
-20 dB
What are the key concepts of gain and attenuation in circuits?
Gain: loss; Attenuation: amplification
Gain: amplification; Attenuation: loss
Gain: resistance; Attenuation: current
Gain: frequency; Attenuation: voltage
How are decibels used in measuring gain and attenuation?
They encrypt large ratios
They express large ratios in smaller figures using logarithms
They simplify voltage gain only
They measure resistance
What is the relationship between gain and attenuation in cascaded circuits?
Gain cancels attenuation completely
Gain can offset attenuation; multiply to get totals
Attenuation always dominates gain
They are unrelated
What can dB systems have in terms of gains or attenuation?
Up to a hundred
Up to a thousand
Up to a million
Unlimited
Why are decibels used for gain and attenuation?
They reduce distortion
They produce smaller, easier figures
They increase accuracy
They eliminate noise
What is the formula for current gain in decibels?
dB = 10 log(Iout / Iin)
dB = 20 log(Iout / Iin)
dB = 30 log(Iout / Iin)
dB = 40 log(Iout / Iin)
How is the output voltage or current ratio calculated?
Find ratio, then multiply log by 20
Multiply ratio by 100
Divide output by input only
Use Ohm’s Law
What is the formula for power gain in decibels?
dB = 20 log(Pout / Pin)
dB = 10 log(Pout / Pin)
dB = 5 log(Pout / Pin)
dB = 100 log(Pout / Pin)
What is the gain in decibels for an amplifier with 4 mV input and 7 V output?
60 dB
64.86 dB
70 dB
50 dB
How are electromagnetic waves characterized?
By constant voltage
By oscillating electric and magnetic fields
By static frequencies
By fixed resistance
How is frequency measured?
In volts
In cycles per second (Hz)
In watts
In ohms
What does one cycle per second equal?
One kilohertz
One hertz (Hz)
One megahertz
One gigahertz
What is the prefix for 1,000?
Mega
Kilo
Giga
Tera
What is the prefix for 1,000,000?
Mega
Giga
Kilo
Tera
What is the prefix for 1,000,000,000?
Tera
Mega
Giga
Kilo
What is the prefix for 1,000,000,000,000?
Kilo
Mega
Giga
Tera
How can a frequency of 8,000,000 be simplified?
8 kHz
8 MHz
8 GHz
8 Hz
How can a frequency of 18,500,000,000 Hz be simplified?
18.5 kHz
18.5 MHz
18.5 GHz
18.5 Hz
What is wavelength?
Distance occupied by one cycle of a wave
Speed of the wave
Frequency of a signal
Voltage amplitude
How is wavelength measured?
In volts
In meters between wave cycles
In decibels
In amperes
What symbol represents wavelength?
Ω
λ
Δ
α
How is wavelength calculated from frequency?
λ = 300,000,000 m/s ÷ f
λ = f ÷ 300,000,000
λ = 20 log f
λ = Vout / Vin
What is the wavelength of a 3,000,000 Hz signal?
30 m
100 m
300 m
3 m
How is wavelength calculated if frequency is in megahertz?
λ (m) = 300 / f(MHz)
λ (m) = f / 300
λ (m) = 20 log f
λ (m) = 300 × f
What is the wavelength of a 3 MHz signal?
30 m
100 m
300 m
3 m
What does the electromagnetic spectrum include?
Only visible light
All frequencies of electromagnetic signals
Only radio signals
Only microwaves
What does the electromagnetic spectrum define?
Sound waves
All kinds of lights, visible and invisible
Only digital codes
Only infrared
What are the commonly used radio frequencies for?
Cooking appliances
Two-way communication, TV, smartphones
Musical instruments
Traffic lights
What is the frequency range for Extremely Low Frequency (ELF)?
30–300 Hz
3–30 Hz
300–3000 Hz
30–300 kHz
What is the frequency range for Voice Frequency (VF)?
30–300 Hz
300–3000 Hz
3–30 kHz
30–300 kHz
What is the frequency range for Very Low Frequency (VLF)?
3–30 Hz
300–3000 Hz
3–30 kHz
30–300 kHz
What is the frequency range for Low Frequency (LF)?
30–300 Hz
30–300 kHz
3–30 kHz
300–3000 Hz
What is the frequency range for Medium Frequency (MF)?
300 Hz–3 kHz
300 kHz–3 MHz
3–30 MHz
30–300 MHz
What is the frequency range for High Frequency (HF)?
30–300 Hz
300 Hz–3 kHz
3–30 MHz
300 MHz–3 GHz
What is the frequency range for Very High Frequency (VHF)?
30–300 MHz
3–30 MHz
300–3000 Hz
3–30 GHz
What is the frequency range for Ultra-High Frequency (UHF)?
30–300 MHz
300 MHz–3 GHz
3–30 GHz
30–300 GHz
What is the frequency range for Super High Frequency (SHF)?
3–30 GHz
30–300 MHz
300 kHz–3 MHz
30–300 GHz
What is the frequency range for Extremely High Frequency (EHF)?
30–300 Hz
30–300 kHz
3–30 GHz
30–300 GHz
What is the wavelength range for Infrared?
0.7–10 μm
0.4–0.8 μm
10–100 μm
0.1–0.3 μm
What is the wavelength range for the Visible Spectrum?
0.7–10 μm
0.4–0.8 μm
10–100 μm
0.1–0.3 μm
What type of communication is half-duplex?
One-way only
Two-way simultaneous
Two-way with alternating directions
No feedback
What is an analog signal?
Digital code
A continuously varying voltage or current
Morse symbols
Stored data
What is a sine wave?
A single-frequency analog signal
A binary code
A noise waveform
A DC voltage
How do voice and video voltages behave as analog signals?
They remain constant
They vary based on sound or light variations
They exist in discrete increments
They only transmit binary
What produces analog signals when detected by a sensor?
Mechanical gears
Physical characteristics like temperature or light
Digital processors
Binary encoders
How do digital signals differ from analog signals?
They vary continuously
They vary in discrete increments
They use sine waves only
They carry no data
What does Morse code use to represent letters and numbers?
Binary code
Short (dots) and long (dashes) signals
Light waves
Frequency modulation
What is the length of a dot in Morse code?
One unit
Two units
Three units
Four units
How long is a dash in Morse code?
One unit
Two units
Three units
Four units
What is the space between parts of the same letter in Morse code?
One unit
Two units
Three units
Four units
How long is the space between letters in Morse code?
One unit
Two units
Three units
Seven units
What is the space between words in Morse code?
Three units
Five units
Seven units
Nine units
What is continuous-wave (CW) code also known as?
Digital modulation
Radio telegraphy
Optical signaling
Binary transmission
How does CW code represent dots and dashes?
By changing amplitude
By turning a sine wave on and off
By using binary numbers
By varying frequency
What do binary codes represent?
Only numbers
Numbers, letters, or special symbols
Only audio signals
Only visible light
What is ASCII?
A type of analog signal
A type of modulation
The most commonly used digital communication code
A wavelength measurement
How are binary codes transferred?
Through handwriting
Through wire, radio, or optical medium
Only through satellites
Only through printed text
