WorksheetsQuiz on Electronic Communication
Total questions: 35
Worksheet time: 6mins
Which of the following best defines electronic communication?
Transmission of information over optical media
Analog processing of audio signals
Transmission and reception of information using electronic signals
Digital storage of data
What is the main advantage of digital communication systems over analog systems?
Lower cost
Higher noise immunity
Reduced bandwidth requirements
Simplified circuitry
The electromagnetic spectrum is divided into bands primarily based on:
Modulation type
Power level
Frequency range
Communication protocols
Which layer of the OSI model is responsible for signal modulation?
Network layer
Physical layer
Data link layer
Application layer
In communication systems, attenuation refers to:
Increase in signal amplitude
Reduction in signal strength over distance
Noise addition to the signal
Signal reflection at boundaries
In a capacitor, the reactance decreases as the:
Capacitance decreases
Voltage increases
Frequency increases
Temperature decreases
The purpose of a diode in a rectifier circuit is to:
Store charge
Allow current flow in one direction only
Amplify the signal
Regulate voltage
The gain of an operational amplifier in inverting mode is determined by:
Supply voltage
Load resistance
Feedback resistor and input resistor ratio
Input signal amplitude
In transistor operation, the region where both junctions are forward-biased is called the:
Cutoff region
Saturation region
Active region
Reverse region
The bandwidth of an RC low-pass filter is determined by:
The load resistance
The DC supply voltage
The RC time constant
The peak input voltage
The modulation index for AM is given by:
Vc/Vm
Vm/Vc
Vc×Vm
Vc−Vm
In an AM signal, the total power is:
Proportional to the modulation index squared
Independent of carrier power
Carrier power plus sideband power
Twice the carrier power
For overmodulation in AM, the modulation index exceeds:
0.5
1.0
2.0
Infinity
Double-sideband suppressed carrier (DSB-SC) transmission eliminates:
Noise interference
Upper and lower sidebands
Carrier signal
Modulating signal
The efficiency of an AM signal improves with:
Higher carrier amplitude
Higher modulation index
Increased carrier frequency
Decreased sideband power
The modulation index in FM is defined as:
Ratio of frequency deviation to modulating frequency
Product of carrier and modulating frequencies
Inverse of the modulation sensitivity
Ratio of carrier frequency to deviation
Noise immunity in FM is enhanced due to:
Higher carrier amplitude
Constant amplitude and increased deviation
Reduced modulation index
Variable amplitude modulation
For narrowband FM, the deviation ratio is typically:
Greater than 10
Equal to 1
Less than 1
Undefined
The Carson's rule for FM bandwidth states that:
Bandwidth = 2 × carrier frequency
Bandwidth = 2 × (frequency deviation + modulating frequency)
Bandwidth = frequency deviation/modulation index
Bandwidth = modulating frequency × deviation
The primary advantage of FM over AM is:
Reduced bandwidth
Better noise rejection
Simplified receiver design
Lower transmission power
The RF oscillator in a transmitter generates the:
Modulating signal
Carrier signal
Audio signal
Sideband frequencies
Which amplifier class is most efficient for RF transmission?
Class A
Class B
Class C
Class AB
An AM transmitter typically uses a high-level modulation method for:
Improved noise immunity
Simplified circuitry
High-power output
Increased bandwidth
In FM transmitters, the frequency multiplier is used to:
Improve linearity
Enhance sensitivity
Increase carrier frequency
Reduce noise
The purpose of a directional coupler in a transmitter is to:
Generate the carrier wave
Amplify the RF signal
Measure transmitted and reflected power
Stabilize the oscillator
The sensitivity of a receiver refers to its ability to:
Suppress noise
Detect weak signals
Maximize bandwidth
Enhance power gain
The image frequency problem in a superheterodyne receiver can be reduced by:
Increasing the IF frequency
Improving RF selectivity
Decreasing the local oscillator frequency
Using a wider filter bandwidth
Automatic gain control (AGC) in receivers is used to:
Maintain tuning stability
Suppress harmonics
Stabilize output signal amplitude
Adjust IF frequency
The role of a mixer in a receiver is to:
Amplify weak signals
Filter out noise
Combine RF and LO signals to produce IF
Adjust bandwidth
The IF amplifier in a superheterodyne receiver primarily enhances:
Sensitivity
Selectivity
Frequency stability
Demodulation accuracy
TDM operates by:
Assigning unique frequencies to each signal
Allocating distinct time slots to signals
Combining signals using phase difference
Modulating signal amplitude
In FDM systems, guard bands are used to:
Improve signal-to-noise ratio
Reduce signal power
Prevent adjacent channel interference
Enhance data rates
A pilot tone is used in multiplexing to:
Measure signal-to-noise ratio
Synchronize receiver and transmitter
Filter out noise
Amplify high-frequency signals
Statistical TDM improves bandwidth utilization by:
Allocating slots dynamically based on demand
Using fixed time slots
Increasing guard times
Operating at constant bit rates
In WDM systems, channels are separated by:
Phase difference
Time delay
Wavelength
Frequency
