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All questions of Communication Systems for JEE Exam
What should be the approximate height of antenna if the TV telecast is to cover a radius of 100 km?- a)128 m
- b)78 m
- c)781 m
- d)1280 m
Correct answer is option 'C'. Can you explain this answer?
What should be the approximate height of antenna if the TV telecast is to cover a radius of 100 km?
a)
128 m
b)
78 m
c)
781 m
d)
1280 m
|
Aayush Agarwal answered |
The answer is derived from the expression r= whole root of (2 x radius of earth x height of tower) where r stands for radius of the area or the distance to be covered. radius of earth and height of tower are in km. put the values and get the answer.
Optical communication using fibres is performed in the frequency range of- a)few kHz
- b)54-72 MHz
- c)1THz to 1000 THz
- d)30-40 MHz
Correct answer is option 'C'. Can you explain this answer?
Optical communication using fibres is performed in the frequency range of
a)
few kHz
b)
54-72 MHz
c)
1THz to 1000 THz
d)
30-40 MHz
|
Jhanvi Sengupta answered |
Optical communication using fibres is performed in the frequency range of 1 THz to 1000 THz.
Frequency Range for Optical Communication
Optical communication is a method of transmitting information using light as a carrier signal. It is performed using optical fibres that are made of glass or plastic. The frequency range of optical communication is very high as compared to other methods of communication. The following are the frequency ranges for different types of communication:
- Radio communication: 3 kHz to 300 GHz
- Microwave communication: 300 MHz to 300 GHz
- Infrared communication: 300 GHz to 400 THz
- Visible light communication: 400 THz to 800 THz
- Ultraviolet communication: 800 THz to 30 PHz
Frequency Range for Optical Fibre Communication
Optical fibre communication is performed using a specific wavelength of light. The wavelength of light is measured in nanometers (nm). The following are the wavelength ranges for different types of optical fibres:
- Single-mode fibre: 1260 nm to 1625 nm
- Multimode fibre: 850 nm to 1300 nm
The frequency of light can be calculated using the equation:
Frequency = Speed of light / Wavelength
The speed of light is approximately 3 x 10^8 m/s. Using this, we can calculate the frequency range of optical fibre communication as:
Frequency range = Speed of light / Wavelength range
= (3 x 10^8 m/s) / (1260 nm to 1625 nm)
= 1 THz to 1000 THz
Hence, the correct option is C, i.e., 1 THz to 1000 THz.
Frequency Range for Optical Communication
Optical communication is a method of transmitting information using light as a carrier signal. It is performed using optical fibres that are made of glass or plastic. The frequency range of optical communication is very high as compared to other methods of communication. The following are the frequency ranges for different types of communication:
- Radio communication: 3 kHz to 300 GHz
- Microwave communication: 300 MHz to 300 GHz
- Infrared communication: 300 GHz to 400 THz
- Visible light communication: 400 THz to 800 THz
- Ultraviolet communication: 800 THz to 30 PHz
Frequency Range for Optical Fibre Communication
Optical fibre communication is performed using a specific wavelength of light. The wavelength of light is measured in nanometers (nm). The following are the wavelength ranges for different types of optical fibres:
- Single-mode fibre: 1260 nm to 1625 nm
- Multimode fibre: 850 nm to 1300 nm
The frequency of light can be calculated using the equation:
Frequency = Speed of light / Wavelength
The speed of light is approximately 3 x 10^8 m/s. Using this, we can calculate the frequency range of optical fibre communication as:
Frequency range = Speed of light / Wavelength range
= (3 x 10^8 m/s) / (1260 nm to 1625 nm)
= 1 THz to 1000 THz
Hence, the correct option is C, i.e., 1 THz to 1000 THz.
AM detection is- a)detecting whether it is modulated
- b)finding the type of modulation
- c)recovering the modulating signal from the received signal
- d)none of these
Correct answer is option 'C'. Can you explain this answer?
AM detection is
a)
detecting whether it is modulated
b)
finding the type of modulation
c)
recovering the modulating signal from the received signal
d)
none of these
|
|
Raza Great answered |
AM Detector. The detection of AM radio signals is a diode application. The modulated AM carrier wave is received by the antenna of the radio receiver and is rectified by the action of a detector diode. ... The signal frequency which modulates it is much lower, 0.02 to 5 kHz, and it can pass through the filter
Super high frequencies of __________ are used in Radar and Satellite Communication.- a)2000 to 25000 MHz
- b)3000 to 30000 MHz
- c)1000 to 10000 MHz
- d)5000 to 30000 MHz
Correct answer is option 'B'. Can you explain this answer?
Super high frequencies of __________ are used in Radar and Satellite Communication.
a)
2000 to 25000 MHz
b)
3000 to 30000 MHz
c)
1000 to 10000 MHz
d)
5000 to 30000 MHz
|
Aarya Khanna answered |
Radar and Satellite Communication Frequencies
Radar and satellite communication systems utilize high frequencies for their operations. These frequencies fall within the super high frequency (SHF) range, which typically ranges from 3 to 30 gigahertz (GHz). Among the given options, option 'B' falls within this range, making it the correct answer.
Explanation:
Super High Frequency (SHF)
- Super high frequency (SHF) is a range of electromagnetic frequencies that spans from 3 to 30 gigahertz (GHz). It is also sometimes referred to as the centimeter band due to the wavelengths being in the range of 1 to 10 centimeters.
- SHF frequencies are commonly used in various applications, including radar systems, satellite communication, microwave ovens, wireless local area networks (WLANs), and more.
Radar Systems
- Radar (Radio Detection and Ranging) is a technology used to detect and track objects by transmitting radio waves and analyzing the reflected signals. It is widely used in military, aviation, weather forecasting, and traffic control.
- Radar systems typically operate in the SHF range due to several advantages such as higher resolution, increased accuracy, and reduced interference from atmospheric conditions.
- The SHF range provides a balance between signal attenuation and atmospheric absorption, making it suitable for long-range radar applications.
Satellite Communication
- Satellite communication involves the use of artificial satellites to relay signals between two or more locations on Earth. It is widely used for television broadcasting, telephone calls, internet connectivity, and remote sensing.
- SHF frequencies are commonly used in satellite communication due to their ability to provide high data transfer rates and large bandwidths. These frequencies allow for the transmission of a large amount of information, making them ideal for applications that require high-speed data transfer.
- Additionally, SHF frequencies experience less interference and have a higher resistance to rain attenuation compared to lower frequency bands, making them suitable for reliable and efficient satellite communication.
Conclusion
In conclusion, super high frequencies within the range of 3 to 30 gigahertz (GHz) are used in radar and satellite communication systems. These frequencies offer advantages such as higher resolution, increased accuracy, larger bandwidths, and better resistance to interference and atmospheric conditions.
Radar and satellite communication systems utilize high frequencies for their operations. These frequencies fall within the super high frequency (SHF) range, which typically ranges from 3 to 30 gigahertz (GHz). Among the given options, option 'B' falls within this range, making it the correct answer.
Explanation:
Super High Frequency (SHF)
- Super high frequency (SHF) is a range of electromagnetic frequencies that spans from 3 to 30 gigahertz (GHz). It is also sometimes referred to as the centimeter band due to the wavelengths being in the range of 1 to 10 centimeters.
- SHF frequencies are commonly used in various applications, including radar systems, satellite communication, microwave ovens, wireless local area networks (WLANs), and more.
Radar Systems
- Radar (Radio Detection and Ranging) is a technology used to detect and track objects by transmitting radio waves and analyzing the reflected signals. It is widely used in military, aviation, weather forecasting, and traffic control.
- Radar systems typically operate in the SHF range due to several advantages such as higher resolution, increased accuracy, and reduced interference from atmospheric conditions.
- The SHF range provides a balance between signal attenuation and atmospheric absorption, making it suitable for long-range radar applications.
Satellite Communication
- Satellite communication involves the use of artificial satellites to relay signals between two or more locations on Earth. It is widely used for television broadcasting, telephone calls, internet connectivity, and remote sensing.
- SHF frequencies are commonly used in satellite communication due to their ability to provide high data transfer rates and large bandwidths. These frequencies allow for the transmission of a large amount of information, making them ideal for applications that require high-speed data transfer.
- Additionally, SHF frequencies experience less interference and have a higher resistance to rain attenuation compared to lower frequency bands, making them suitable for reliable and efficient satellite communication.
Conclusion
In conclusion, super high frequencies within the range of 3 to 30 gigahertz (GHz) are used in radar and satellite communication systems. These frequencies offer advantages such as higher resolution, increased accuracy, larger bandwidths, and better resistance to interference and atmospheric conditions.
Repeater stations are used to- a)to extract the message signal from the received signals
- b)repeat the same program in different areas
- c)translate the same program into different languages
- d)to extend the range of a communication system
Correct answer is option 'D'. Can you explain this answer?
Repeater stations are used to
a)
to extract the message signal from the received signals
b)
repeat the same program in different areas
c)
translate the same program into different languages
d)
to extend the range of a communication system
|
Osheen Bishnoi answered |
Repeater stations are use to extend range of communication..as they receives the signals and retransmits them on a different frequency
A message of frequency 5 kHz and peak voltage of 2 V is used to modulate a carrier wave of frequency 2 MHz and a peak voltage of 10 V. The modulation index is- a)0.01
- b)0.2
- c)0.1
- d)1
Correct answer is option 'B'. Can you explain this answer?
A message of frequency 5 kHz and peak voltage of 2 V is used to modulate a carrier wave of frequency 2 MHz and a peak voltage of 10 V. The modulation index is
a)
0.01
b)
0.2
c)
0.1
d)
1
|
Anand Kumar answered |
It's very simple.
Use formula, Em/ Ec.
where,
(Em-peak voltage of message signal.
Ec - Peak voltage of carrier wave.)
Am = 2/10
= 0.2
Use formula, Em/ Ec.
where,
(Em-peak voltage of message signal.
Ec - Peak voltage of carrier wave.)
Am = 2/10
= 0.2
Multiplexing is a scheme for transmitting multiple signals at the same time e.g. speeches of ten persons in different rooms on the same channel. How many transmitters will be required in any multiplexing scheme?- a)one
- b)three
- c)two
- d)ten
Correct answer is option 'A'. Can you explain this answer?
Multiplexing is a scheme for transmitting multiple signals at the same time e.g. speeches of ten persons in different rooms on the same channel. How many transmitters will be required in any multiplexing scheme?
a)
one
b)
three
c)
two
d)
ten
|
|
Vivek answered |
As only one signal is transmitted by the multiplexer, only one transmitter is required.
The process of impressing any information by changing the original signal is called- a)modulation
- b)diffraction
- c)transmission
- d)attenuation
Correct answer is option 'A'. Can you explain this answer?
The process of impressing any information by changing the original signal is called
a)
modulation
b)
diffraction
c)
transmission
d)
attenuation
|
Hansa Sharma answered |
The process of impressing information by changing the original signal is called ‘modulation’, and it is done in a variety of ways. In all cases the radio waves simply act as a vehicle for the information, so they are commonly called ‘carrier waves’.
To reduce the distortion in amplitude modulation, modulation index is kept- a)large
- b)very large
- c)small
- d)equal to 1
Correct answer is option 'C'. Can you explain this answer?
To reduce the distortion in amplitude modulation, modulation index is kept
a)
large
b)
very large
c)
small
d)
equal to 1
|
Swati Verma answered |
In Amplitude modulation, it is defined as the ratio of the amplitude of modulating signal to that of the carrier signal. Its value is kept less than 1 to avoid overmodulation which leads to distortions in the modulated signal and makes it very hard to demodulate and extract the modulating signal.
TV set used in a typical house is- a)a channel
- b)a repeater
- c)a receiver
- d)a transmitter
Correct answer is option 'C'. Can you explain this answer?
TV set used in a typical house is
a)
a channel
b)
a repeater
c)
a receiver
d)
a transmitter
|
|
Aarya Khanna answered |
The correct answer is option 'C': a receiver.
Explanation:
A TV set is a device that is used to receive television signals and display them as audio and visual content on a screen. Let's break down the explanation further:
1. TV Set: A TV set, also known as a television or television receiver, is an electronic device used for watching television programs. It consists of a display screen, built-in speakers or audio output, and various controls for adjusting settings such as volume, channel selection, and picture quality.
2. Receiver: In the context of television, a receiver is a device that receives television signals and converts them into audio and visual content that can be displayed on a TV screen. The TV set acts as a receiver by accepting incoming signals and decoding them to produce the desired television program or content.
3. Television Signals: Television signals are transmitted through electromagnetic waves. These signals are generated by TV stations or broadcasters and contain audio and video information that represents the television program being transmitted. The TV set receives these signals and processes them to display the program on the screen.
4. Channel Selection: A TV set allows users to select different channels to access various television programs. Channels are specific frequencies or frequency ranges used for broadcasting different programs. The TV set receives the selected channel's signal and displays the corresponding program on the screen.
5. Additional Functionality: Modern TV sets often have additional features and capabilities, such as the ability to connect to the internet, access streaming services, or display content from external devices. However, the core function of a TV set is to receive television signals and display them as audio and visual content.
In summary, a TV set is primarily a receiver that accepts television signals and converts them into audio and visual content that can be displayed on a screen. It enables users to select channels and watch various television programs.
Explanation:
A TV set is a device that is used to receive television signals and display them as audio and visual content on a screen. Let's break down the explanation further:
1. TV Set: A TV set, also known as a television or television receiver, is an electronic device used for watching television programs. It consists of a display screen, built-in speakers or audio output, and various controls for adjusting settings such as volume, channel selection, and picture quality.
2. Receiver: In the context of television, a receiver is a device that receives television signals and converts them into audio and visual content that can be displayed on a TV screen. The TV set acts as a receiver by accepting incoming signals and decoding them to produce the desired television program or content.
3. Television Signals: Television signals are transmitted through electromagnetic waves. These signals are generated by TV stations or broadcasters and contain audio and video information that represents the television program being transmitted. The TV set receives these signals and processes them to display the program on the screen.
4. Channel Selection: A TV set allows users to select different channels to access various television programs. Channels are specific frequencies or frequency ranges used for broadcasting different programs. The TV set receives the selected channel's signal and displays the corresponding program on the screen.
5. Additional Functionality: Modern TV sets often have additional features and capabilities, such as the ability to connect to the internet, access streaming services, or display content from external devices. However, the core function of a TV set is to receive television signals and display them as audio and visual content.
In summary, a TV set is primarily a receiver that accepts television signals and converts them into audio and visual content that can be displayed on a screen. It enables users to select channels and watch various television programs.
Bandwidth of an electronic communication system- a)is the maximum frequency at which an equipment
- b)is number of bands in the spectrum
- c)is the frequency range over which an equipment operates or the portion of the spectrum occupied by the signal
- d)is the minimum frequency at which an equipment
Correct answer is option 'C'. Can you explain this answer?
Bandwidth of an electronic communication system
a)
is the maximum frequency at which an equipment
b)
is number of bands in the spectrum
c)
is the frequency range over which an equipment operates or the portion of the spectrum occupied by the signal
d)
is the minimum frequency at which an equipment
|
Dishani Kulkarni answered |
Explanation: A range within a band of wavelengths, frequencies, or energies; especially : a range of radio frequencies which is occupied by a modulated carrier wave, which is assigned to a service, or over which a device can operate.
The characteristic impedance of a coaxial wire line is of order- a)1000 ohm
- b)200 ohm
- c)30 ohm
- d)80 ohm
Correct answer is option 'D'. Can you explain this answer?
The characteristic impedance of a coaxial wire line is of order
a)
1000 ohm
b)
200 ohm
c)
30 ohm
d)
80 ohm
|
Kavita Joshi answered |
For a coaxial cable with air dielectric and a shield of a given inner diameter, the attenuation is minimized by choosing the diameter of the inner conductor to give a characteristic impedance of 76.7 Ω. When more common dielectrics are considered, the best-loss impedance drops down to a value between 52–64 Ω.
Before transmission the AM produced by a square law device- a)goes through a voltage amplifier
- b)goes through a current amplifier
- c)goes through a transconductance amplifier
- d)goes through a power amplifier
Correct answer is option 'D'. Can you explain this answer?
Before transmission the AM produced by a square law device
a)
goes through a voltage amplifier
b)
goes through a current amplifier
c)
goes through a transconductance amplifier
d)
goes through a power amplifier
|
Neha Chauhan answered |
Before transmission the AM produced by a square law device goes through a power amplifier.
With the increase in frequencies more than 2 MHz, Ground wave propagation- a)Increases
- b)Fails
- c)Does not depend on the frequency of propagation
- d)None of the above
Correct answer is option 'B'. Can you explain this answer?
With the increase in frequencies more than 2 MHz, Ground wave propagation
a)
Increases
b)
Fails
c)
Does not depend on the frequency of propagation
d)
None of the above
|
Jyoti Kapoor answered |
The ground wave is the preferred propagation type for long distance communication using frequencies below 3 MHz (the earth behaves as a conductor for all frequencies below 5 MHz). The ground wave is also used for short distance communications using frequencies between 3 and 30 MHz.
Pulse is specified by pulse height or the peak voltage, the pulse duration and pulse to pulse spacing. In pulse amplitude modulation (PAM) what changes with base band signal is- a)pulse duration
- b)pulse to pulse spacing
- c)none of these
- d)pulse height or the peak voltage
Correct answer is option 'D'. Can you explain this answer?
Pulse is specified by pulse height or the peak voltage, the pulse duration and pulse to pulse spacing. In pulse amplitude modulation (PAM) what changes with base band signal is
a)
pulse duration
b)
pulse to pulse spacing
c)
none of these
d)
pulse height or the peak voltage
|
Sreemoyee Sengupta answered |
Pulseis specified by pulse height or the peak voltage, the pulse duration and pulse to pulse spacing. In pulse amplitude modulation (PAM) what changes with base band signal is pulse height or the peak voltage.
Hence the correct answer is option D.
Hence the correct answer is option D.
Modes of communication system are classified into :- a)Line communication and space communication
- b)Space communication and Digital communication
- c)Point to point communication and broadcast communication
- d)Line communication and analog communication
Correct answer is option 'C'. Can you explain this answer?
Modes of communication system are classified into :
a)
Line communication and space communication
b)
Space communication and Digital communication
c)
Point to point communication and broadcast communication
d)
Line communication and analog communication
|
Anu Basu answered |
There are various modes of communication systems that are classified based on different criteria. One common classification is based on the nature of the communication channel. In this classification, the modes of communication systems are categorized into line communication and space communication, point-to-point communication and broadcast communication, and digital communication and analog communication.
Line Communication and Space Communication:
Line communication refers to the mode of communication where signals are transmitted over a physical medium, such as a wire or a cable. Examples of line communication include telephony, telegraphy, and fax machines. In line communication, the signals are transmitted in a sequential manner, one after the other.
On the other hand, space communication refers to the mode of communication where signals are transmitted through free space, without the need for a physical medium. Examples of space communication include radio waves, microwave communication, and satellite communication. In space communication, the signals are transmitted through electromagnetic waves, which can propagate through space.
Point-to-Point Communication and Broadcast Communication:
Point-to-point communication refers to the mode of communication where signals are transmitted between two specific points or locations. Examples of point-to-point communication include telephone calls and video conferencing. In point-to-point communication, the transmission is usually private and intended for a specific recipient.
In contrast, broadcast communication refers to the mode of communication where signals are transmitted from one point to multiple points. Examples of broadcast communication include television and radio broadcasting. In broadcast communication, the transmission is intended for a wide audience and can be received by multiple recipients simultaneously.
Digital Communication and Analog Communication:
Digital communication refers to the mode of communication where signals are represented as discrete values or digits. Examples of digital communication include computer networks, email, and digital television. In digital communication, the signals are encoded into binary digits (0s and 1s) and transmitted using digital modulation techniques.
Analog communication, on the other hand, refers to the mode of communication where signals are represented as continuous waveforms. Examples of analog communication include traditional telephony, AM/FM radio, and analog television. In analog communication, the signals are transmitted using analog modulation techniques, where the amplitude, frequency, or phase of the carrier wave is varied to encode the information.
In conclusion, the modes of communication systems are classified into line communication and space communication, point-to-point communication and broadcast communication, and digital communication and analog communication. Each classification represents a different characteristic of the communication system and is used in different applications.
Line Communication and Space Communication:
Line communication refers to the mode of communication where signals are transmitted over a physical medium, such as a wire or a cable. Examples of line communication include telephony, telegraphy, and fax machines. In line communication, the signals are transmitted in a sequential manner, one after the other.
On the other hand, space communication refers to the mode of communication where signals are transmitted through free space, without the need for a physical medium. Examples of space communication include radio waves, microwave communication, and satellite communication. In space communication, the signals are transmitted through electromagnetic waves, which can propagate through space.
Point-to-Point Communication and Broadcast Communication:
Point-to-point communication refers to the mode of communication where signals are transmitted between two specific points or locations. Examples of point-to-point communication include telephone calls and video conferencing. In point-to-point communication, the transmission is usually private and intended for a specific recipient.
In contrast, broadcast communication refers to the mode of communication where signals are transmitted from one point to multiple points. Examples of broadcast communication include television and radio broadcasting. In broadcast communication, the transmission is intended for a wide audience and can be received by multiple recipients simultaneously.
Digital Communication and Analog Communication:
Digital communication refers to the mode of communication where signals are represented as discrete values or digits. Examples of digital communication include computer networks, email, and digital television. In digital communication, the signals are encoded into binary digits (0s and 1s) and transmitted using digital modulation techniques.
Analog communication, on the other hand, refers to the mode of communication where signals are represented as continuous waveforms. Examples of analog communication include traditional telephony, AM/FM radio, and analog television. In analog communication, the signals are transmitted using analog modulation techniques, where the amplitude, frequency, or phase of the carrier wave is varied to encode the information.
In conclusion, the modes of communication systems are classified into line communication and space communication, point-to-point communication and broadcast communication, and digital communication and analog communication. Each classification represents a different characteristic of the communication system and is used in different applications.
In which manner does current or voltage vary in an analog signal with time?- a)not a fixed pattern
- b)discontinuously
- c)sometime continuously and sometime discontinuously
- d)continuously
Correct answer is option 'D'. Can you explain this answer?
In which manner does current or voltage vary in an analog signal with time?
a)
not a fixed pattern
b)
discontinuously
c)
sometime continuously and sometime discontinuously
d)
continuously
|
Vijay Bansal answered |
There are two types of signal.
1-Analog
2-Discrete
If we understand them simultaneously then it will be easy.
Signals are represented mathematically as a function of one or more independent variable. Generally as independent variable time is chosen. For example speech signal is represented mathematically by acoustic pressure as function of time.
In analog signal the independent variable that is time axis is continuous ,and thus these signals are defined for continuum of values of independent variable(time).
The limiting values of modulation index (μ) of an AM wave is- a)0 and 1
- b)1 and 10
- c)10 to 100
- d)None of the above
Correct answer is option 'A'. Can you explain this answer?
The limiting values of modulation index (μ) of an AM wave is
a)
0 and 1
b)
1 and 10
c)
10 to 100
d)
None of the above
|
Nitin Nair answered |
For maximum value modulation index can be greater than 1 or it can take any value depending on the amount of carrier present in the overall modulated signal. Maximum value of modulation index in 1. Above 1 over modulation occurs which cause distortion of signal. Minimum value is 0.
Type of modulation used for continuous and sinusoidal wave is- a)Pulse Amplitude modulation
- b)Pulse position modulation
- c)Phase modulation, Amplitude modulation and Frequency Modulation
- d)Pulse frequency modulation and Pulse position modulation
Correct answer is option 'C'. Can you explain this answer?
Type of modulation used for continuous and sinusoidal wave is
a)
Pulse Amplitude modulation
b)
Pulse position modulation
c)
Phase modulation, Amplitude modulation and Frequency Modulation
d)
Pulse frequency modulation and Pulse position modulation
|
|
Manoj Chauhan answered |
Amplitude modulation, Frequency modulation and Phase modulation are used for the carrier wave which is a continuous wave whereas Pulse amplitude modulation, Pulse width modulation and Pulse position modulation is used if the wave is not a continuous one and is in the form of pulses.
FM Radio set used in cars is- a)a channel
- b)a receiver
- c)a transmitter
- d)a repeater
Correct answer is option 'B'. Can you explain this answer?
FM Radio set used in cars is
a)
a channel
b)
a receiver
c)
a transmitter
d)
a repeater
|
Ishita Deshpande answered |
Explanation: Radio means sending energy with waves. In other words, it's a method of transmitting electrical energy from one place to another without using any kind of direct, wired connection. That's why it's often called wireless. The equipment that sends out a radio wave is known as a transmitter; the radio wave sent by a transmitter whizzes through the air—maybe from one side of the world to the other—and completes its journey when it reaches a second piece of equipment called a receiver((here a radio).
For attenuation of high frequencies we should use- a)shunt capacitance
- b)series capacitance
- c)inductance
- d)resistance
Correct answer is option 'A'. Can you explain this answer?
For attenuation of high frequencies we should use
a)
shunt capacitance
b)
series capacitance
c)
inductance
d)
resistance
|
|
Aarya Khanna answered |
Attenuation of High Frequencies using Shunt Capacitance
Introduction
Attenuation of high frequencies is a common requirement in many electronic circuits. High frequencies can introduce noise and interference, affecting the performance and accuracy of the circuit. To eliminate or reduce these unwanted high-frequency signals, various techniques can be employed. One such technique is the use of shunt capacitance.
Explanation
1. Shunt Capacitance
Shunt capacitance refers to the placement of a capacitor in parallel or shunt with the load or component to be protected. This configuration allows the capacitor to provide a low impedance path for high-frequency signals, effectively diverting them away from the circuit.
2. High Pass Filter
When a shunt capacitor is used in a circuit, it forms a high-pass filter with the load or component. A high-pass filter allows high-frequency signals to pass through while attenuating or blocking low-frequency signals. In this case, the shunt capacitor acts as a frequency-dependent impedance, providing a low impedance path for high-frequency signals and a high impedance path for low-frequency signals.
3. Capacitive Reactance
The impedance offered by a capacitor to an AC signal is called capacitive reactance. Capacitive reactance is inversely proportional to frequency and is given by the formula Xc = 1/(2πfC), where Xc is the capacitive reactance, f is the frequency, and C is the capacitance. At higher frequencies, the capacitive reactance decreases, allowing more current to flow through the shunt capacitor.
4. Attenuation of High Frequencies
By providing a low impedance path for high-frequency signals, the shunt capacitor effectively attenuates or reduces their amplitude. This helps in reducing noise and interference caused by high-frequency signals, resulting in improved circuit performance.
Comparison with Other Options
- Series Capacitance: Series capacitance is not suitable for attenuating high frequencies as it increases the impedance at higher frequencies, effectively blocking them from passing through.
- Inductance: Inductance is also not suitable as it offers high impedance to high-frequency signals, allowing them to pass through without attenuation.
- Resistance: Resistance does not have a frequency-dependent characteristic like capacitance. It does not provide the desired attenuation for high-frequency signals.
Conclusion
In conclusion, shunt capacitance is the most suitable option for attenuating high frequencies. By providing a low impedance path for high-frequency signals, the shunt capacitor effectively diverts them away from the circuit, reducing noise and interference. It acts as a frequency-dependent impedance, allowing high-frequency signals to pass through while attenuating low-frequency signals.
Introduction
Attenuation of high frequencies is a common requirement in many electronic circuits. High frequencies can introduce noise and interference, affecting the performance and accuracy of the circuit. To eliminate or reduce these unwanted high-frequency signals, various techniques can be employed. One such technique is the use of shunt capacitance.
Explanation
1. Shunt Capacitance
Shunt capacitance refers to the placement of a capacitor in parallel or shunt with the load or component to be protected. This configuration allows the capacitor to provide a low impedance path for high-frequency signals, effectively diverting them away from the circuit.
2. High Pass Filter
When a shunt capacitor is used in a circuit, it forms a high-pass filter with the load or component. A high-pass filter allows high-frequency signals to pass through while attenuating or blocking low-frequency signals. In this case, the shunt capacitor acts as a frequency-dependent impedance, providing a low impedance path for high-frequency signals and a high impedance path for low-frequency signals.
3. Capacitive Reactance
The impedance offered by a capacitor to an AC signal is called capacitive reactance. Capacitive reactance is inversely proportional to frequency and is given by the formula Xc = 1/(2πfC), where Xc is the capacitive reactance, f is the frequency, and C is the capacitance. At higher frequencies, the capacitive reactance decreases, allowing more current to flow through the shunt capacitor.
4. Attenuation of High Frequencies
By providing a low impedance path for high-frequency signals, the shunt capacitor effectively attenuates or reduces their amplitude. This helps in reducing noise and interference caused by high-frequency signals, resulting in improved circuit performance.
Comparison with Other Options
- Series Capacitance: Series capacitance is not suitable for attenuating high frequencies as it increases the impedance at higher frequencies, effectively blocking them from passing through.
- Inductance: Inductance is also not suitable as it offers high impedance to high-frequency signals, allowing them to pass through without attenuation.
- Resistance: Resistance does not have a frequency-dependent characteristic like capacitance. It does not provide the desired attenuation for high-frequency signals.
Conclusion
In conclusion, shunt capacitance is the most suitable option for attenuating high frequencies. By providing a low impedance path for high-frequency signals, the shunt capacitor effectively diverts them away from the circuit, reducing noise and interference. It acts as a frequency-dependent impedance, allowing high-frequency signals to pass through while attenuating low-frequency signals.
If an antenna radiates electromagnetic waves from a height h, then the range d upto which the signal can be detected is given by (R is the radius of the earth)- a)d = √2RH
- b)d = 2Rlh
- c)d = 2Rl√h
- d)d = 2Rh
Correct answer is option 'A'. Can you explain this answer?
If an antenna radiates electromagnetic waves from a height h, then the range d upto which the signal can be detected is given by (R is the radius of the earth)
a)
d = √2RH
b)
d = 2Rlh
c)
d = 2Rl√h
d)
d = 2Rh
|
|
Ankita Datta answered |
Let O be the centre and R is the radius of the earth. PQ is a T.V. antenna of height h. Two tangents QT and QS are drawn from the top Q of the tower. T.V. signal can reach to the point S and T only not at other area:
∠QTO=90[TO⊥QT]
In ΔQTO,
OQ2=OT2+TQ2
OQ=R+h, QT=d, OT=R,
(R+h)2=R2+d2
R2+h2+2Rh=R2+d2
d2=h2+2Rh h⋘R neglect
d2=2Rh
d= √2Rh
∠QTO=90[TO⊥QT]
In ΔQTO,
OQ2=OT2+TQ2
OQ=R+h, QT=d, OT=R,
(R+h)2=R2+d2
R2+h2+2Rh=R2+d2
d2=h2+2Rh h⋘R neglect
d2=2Rh
d= √2Rh
Electronic communication is not possible if- a)message or information is not available in the form of electrical signals
- b)if smell or touch is to be transmitted
- c)if the temperature is high
- d)if the humidity is high
Correct answer is option 'A'. Can you explain this answer?
Electronic communication is not possible if
a)
message or information is not available in the form of electrical signals
b)
if smell or touch is to be transmitted
c)
if the temperature is high
d)
if the humidity is high
|
Sravya Datta answered |
Explanation:As the information or message is transmitted from the source to the receiver ,it is first converted into electrical signal which is then transmiited through the communication medium.Hence in electrical communication it is must to convert raw message or information into electrical signal.Else the electronic messages will not be transmitted.
Electronic communication refers to- a)transfer of information or messages encoded in electrical signals
- b)transfer of electricity from one point to another
- c)transfer of messages encoded in electrical signals
- d)transfer of information encoded in electrical signals
Correct answer is option 'A'. Can you explain this answer?
Electronic communication refers to
a)
transfer of information or messages encoded in electrical signals
b)
transfer of electricity from one point to another
c)
transfer of messages encoded in electrical signals
d)
transfer of information encoded in electrical signals
|
Maitri Sharma answered |
Explanation:When information are sent from one point to the other it has to be converted into electrical signal using transducer.The receiver receives it in its original from using receiver.Such from of communication is called electronic communication.
Which of the following is not a valid option for modulation of waves?- a)phase modulation
- b)frequency modulation
- c)amplitude modulation
- d)velocity modulation
Correct answer is option 'D'. Can you explain this answer?
Which of the following is not a valid option for modulation of waves?
a)
phase modulation
b)
frequency modulation
c)
amplitude modulation
d)
velocity modulation
|
Akshay Shah answered |
If you want to throw a piece of paper at some distance, say 50 m then what will you do? A very simple solution is that you wrap the paper on the stone and then throw it right. So that is the philosophy of modulation. You modulate the carrier signal (stone) with your information signal (paper) and then throw it using a transmitter so that your information can travel to a longer distance. At the receiver side of the communication system the demodulater separates the information signal from the carrier and then your information signal is processed.
The waveform of information, which is being impressed upon the carrier wave, is called the.- a)Carrier wave
- b)Communication wave
- c)Modulating wave
- d)None of the above
Correct answer is option 'C'. Can you explain this answer?
The waveform of information, which is being impressed upon the carrier wave, is called the.
a)
Carrier wave
b)
Communication wave
c)
Modulating wave
d)
None of the above
|
Rajat Patel answered |
In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted.
What happens to the power in a FM signal as the modulation index increases?- a)decreases
- b)increases
- c)randomly changes
- d)remains constant
Correct answer is option 'D'. Can you explain this answer?
What happens to the power in a FM signal as the modulation index increases?
a)
decreases
b)
increases
c)
randomly changes
d)
remains constant
|
Anjali Iyer answered |
As the modulating frequency decreases and the modulating voltage amplitude remains constant, the modulation index increases. This helps in differentiating frequency modulation from phase modulation. The more the amount by which carrier frequency is varied from its unmodulated value, the more is the index of modulation.
Audio signals have a maximum bandwidth of about- a)20 kHz
- b)200 kHz
- c)2000 kHz
- d)2 kHz
Correct answer is option 'A'. Can you explain this answer?
Audio signals have a maximum bandwidth of about
a)
20 kHz
b)
200 kHz
c)
2000 kHz
d)
2 kHz
|
Sreemoyee Choudhury answered |
22050Hz (often lazily called "22 kHz") has been a reasonably popular sample rate for low bit rate MP3s such as 64 kbps in years past. Audio quality is significantly affected, with higher frequency content missing. With the general rise in the availability of large file storage space and faster data links, 22 kHz is now of more limited use.
1.For speech recording where perceived quality is unimportant, but clarity must be maintained.
2.AM radio
3.Formerly used to squeeze much mp3 music onto floppy disk & very small mp3 players.
1.For speech recording where perceived quality is unimportant, but clarity must be maintained.
2.AM radio
3.Formerly used to squeeze much mp3 music onto floppy disk & very small mp3 players.
The range of an AM broadcast depends- a)antenna power and carrier frequency
- b)carrier frequency only
- c)antenna power only
- d)none of these
Correct answer is option 'A'. Can you explain this answer?
The range of an AM broadcast depends
a)
antenna power and carrier frequency
b)
carrier frequency only
c)
antenna power only
d)
none of these
|
Siddharth Tiwari answered |
Explanation:
The range of an AM broadcast depends on two main factors - antenna power and carrier frequency.
Antenna Power:
The power of the transmitting antenna determines the strength of the signal that is radiated into space. A higher power antenna will emit a stronger signal which can travel further before being attenuated by the atmosphere.
Carrier Frequency:
The carrier frequency of an AM broadcast is the frequency at which the signal is transmitted. The range of an AM broadcast depends on the frequency of the carrier wave. Higher frequency signals have shorter wavelengths and are more easily absorbed by the atmosphere, limiting their range. Lower frequency signals have longer wavelengths and can travel further before being absorbed.
Conclusion:
In summary, the range of an AM broadcast depends on both the antenna power and carrier frequency. A higher power antenna and lower carrier frequency will result in a longer range for the broadcast signal.
The range of an AM broadcast depends on two main factors - antenna power and carrier frequency.
Antenna Power:
The power of the transmitting antenna determines the strength of the signal that is radiated into space. A higher power antenna will emit a stronger signal which can travel further before being attenuated by the atmosphere.
Carrier Frequency:
The carrier frequency of an AM broadcast is the frequency at which the signal is transmitted. The range of an AM broadcast depends on the frequency of the carrier wave. Higher frequency signals have shorter wavelengths and are more easily absorbed by the atmosphere, limiting their range. Lower frequency signals have longer wavelengths and can travel further before being absorbed.
Conclusion:
In summary, the range of an AM broadcast depends on both the antenna power and carrier frequency. A higher power antenna and lower carrier frequency will result in a longer range for the broadcast signal.
One method of producing an amplitude modulation is to add the carrier and modulating signal and then- a)a square law device followed by a low pass filter
- b)a cubic law device followed by a high pass filter
- c)a cubic law device followed by a low pass filter
- d)a square law device followed by a high pass filter
Correct answer is option 'A'. Can you explain this answer?
One method of producing an amplitude modulation is to add the carrier and modulating signal and then
a)
a square law device followed by a low pass filter
b)
a cubic law device followed by a high pass filter
c)
a cubic law device followed by a low pass filter
d)
a square law device followed by a high pass filter
|
Mansi Nair answered |
a square law device is used, to eliminate the need of generating a carrier at the receiver end as a demodulator. the result of a square law will have the desired component as well as harmonics. To suppress these harmonics, a bandpass filter (sometimes low pass) is used.
A woofer should be fed from the input through a- a)low pass filter
- b)high pass filter
- c)band pass filter
- d)band stop filter
Correct answer is option 'A'. Can you explain this answer?
A woofer should be fed from the input through a
a)
low pass filter
b)
high pass filter
c)
band pass filter
d)
band stop filter
|
Charvi Ahuja answered |
Woofer is a low frequency loud speaker covering the range 16 Hz to 500 Hz.
For a signal to be reproduced without distortion- a)only the fundamental is required
- b)only the fundamental and first harmonic is required
- c)all the harmonics should be present
- d)none of these
Correct answer is option 'C'. Can you explain this answer?
For a signal to be reproduced without distortion
a)
only the fundamental is required
b)
only the fundamental and first harmonic is required
c)
all the harmonics should be present
d)
none of these
|
|
Anjali Iyer answered |
Most vibrating objects have more than one resonant frequency and those used in musical instruments typically vibrate at harmonics of the fundamental. A harmonic is defined as an integer (whole number) multiple of the fundamental frequency.
Coaxial cables have a bandwidth in the range of- a)750 MHz
- b)750 Hz
- c)750 kHz
- d)750 GHz
Correct answer is option 'A'. Can you explain this answer?
Coaxial cables have a bandwidth in the range of
a)
750 MHz
b)
750 Hz
c)
750 kHz
d)
750 GHz
|
|
Neha Chauhan answered |
Coaxial cables are widely used for transmitting high-frequency signals over long distances. They consist of a central conductor, which is surrounded by a dielectric insulator, and a metallic outer conductor. The bandwidth of a coaxial cable refers to the range of frequencies over which the cable can transmit signals without significant attenuation or distortion.
Bandwidth of Coaxial Cables
The bandwidth of coaxial cables depends on several factors, including the diameter of the cable, the thickness of the insulator, and the material used for the conductors. Generally, the larger the diameter of the cable and the thicker the insulator, the higher the bandwidth.
The bandwidth of coaxial cables is typically measured in megahertz (MHz), which represents millions of cycles per second. A coaxial cable with a bandwidth of 750 MHz means that it can transmit signals with frequencies up to 750 MHz without significant degradation.
Importance of Bandwidth
The bandwidth of a coaxial cable is an important factor to consider when choosing a cable for a particular application. Higher bandwidth cables are typically more expensive and may require more sophisticated hardware to transmit and receive signals. However, they are necessary for applications that require high data transfer rates, such as video streaming or high-speed internet.
Conclusion
In conclusion, the correct answer to the question is option 'A', which states that coaxial cables have a bandwidth in the range of 750 MHz. This means that coaxial cables can transmit signals with frequencies up to 750 MHz without significant degradation, making them suitable for a wide range of applications that require high-speed data transfer.
Bandwidth of Coaxial Cables
The bandwidth of coaxial cables depends on several factors, including the diameter of the cable, the thickness of the insulator, and the material used for the conductors. Generally, the larger the diameter of the cable and the thicker the insulator, the higher the bandwidth.
The bandwidth of coaxial cables is typically measured in megahertz (MHz), which represents millions of cycles per second. A coaxial cable with a bandwidth of 750 MHz means that it can transmit signals with frequencies up to 750 MHz without significant degradation.
Importance of Bandwidth
The bandwidth of a coaxial cable is an important factor to consider when choosing a cable for a particular application. Higher bandwidth cables are typically more expensive and may require more sophisticated hardware to transmit and receive signals. However, they are necessary for applications that require high data transfer rates, such as video streaming or high-speed internet.
Conclusion
In conclusion, the correct answer to the question is option 'A', which states that coaxial cables have a bandwidth in the range of 750 MHz. This means that coaxial cables can transmit signals with frequencies up to 750 MHz without significant degradation, making them suitable for a wide range of applications that require high-speed data transfer.
Amplification is the- a)increase in voltage or power of an electrical signal
- b)decrease in voltage or power of an electrical signal
- c)decrease in power
- d)decrease in voltage
Correct answer is option 'A'. Can you explain this answer?
Amplification is the
a)
increase in voltage or power of an electrical signal
b)
decrease in voltage or power of an electrical signal
c)
decrease in power
d)
decrease in voltage
|
|
Aarya Khanna answered |
Explanation:
Amplification refers to the increase in voltage or power of an electrical signal. It is a process in which the strength of a signal is increased without distorting the original waveform. Amplification is a fundamental operation in various electronic devices such as amplifiers, audio systems, televisions, radios, and many more.
Types of Amplifiers:
1. Voltage Amplifier: A voltage amplifier increases the voltage level of an input signal while keeping the current constant.
2. Power Amplifier: A power amplifier increases both the voltage and current levels of an input signal.
Amplification Process:
The amplification process involves using active electronic components such as transistors or operational amplifiers (op-amps). These components have the ability to control the flow of electrical current and amplify the input signal.
1. Input Signal: The input signal is the electrical signal that needs to be amplified. It can be a low-level signal generated by a microphone, musical instrument, or any other source.
2. Amplification Circuit: The amplification circuit consists of active electronic components and passive components such as resistors, capacitors, and inductors. The active components, like transistors, are used to control the amplification process.
3. Gain Control: The gain control determines the amount of amplification. It is usually set by adjusting the values of resistors or by using feedback mechanisms.
4. Output Signal: The output signal is the amplified version of the input signal. It has a higher voltage or power level compared to the input signal.
Applications of Amplification:
1. Audio Systems: Amplifiers are used in audio systems to increase the volume of sound signals. They are commonly found in speakers, headphones, and audio amplifiers.
2. Telecommunications: Amplifiers are used in telecommunication systems to boost the strength of weak signals for transmission over long distances.
3. Medical Devices: Amplifiers are used in medical devices such as electrocardiographs (ECGs), electroencephalographs (EEGs), and ultrasound machines to amplify and process biological signals.
4. Instrumentation: Amplifiers are used in scientific instruments and measuring devices to amplify weak electrical signals for accurate measurement and analysis.
In conclusion, amplification refers to the increase in voltage or power of an electrical signal. It plays a crucial role in various electronic devices and has numerous applications in different fields.
Amplification refers to the increase in voltage or power of an electrical signal. It is a process in which the strength of a signal is increased without distorting the original waveform. Amplification is a fundamental operation in various electronic devices such as amplifiers, audio systems, televisions, radios, and many more.
Types of Amplifiers:
1. Voltage Amplifier: A voltage amplifier increases the voltage level of an input signal while keeping the current constant.
2. Power Amplifier: A power amplifier increases both the voltage and current levels of an input signal.
Amplification Process:
The amplification process involves using active electronic components such as transistors or operational amplifiers (op-amps). These components have the ability to control the flow of electrical current and amplify the input signal.
1. Input Signal: The input signal is the electrical signal that needs to be amplified. It can be a low-level signal generated by a microphone, musical instrument, or any other source.
2. Amplification Circuit: The amplification circuit consists of active electronic components and passive components such as resistors, capacitors, and inductors. The active components, like transistors, are used to control the amplification process.
3. Gain Control: The gain control determines the amount of amplification. It is usually set by adjusting the values of resistors or by using feedback mechanisms.
4. Output Signal: The output signal is the amplified version of the input signal. It has a higher voltage or power level compared to the input signal.
Applications of Amplification:
1. Audio Systems: Amplifiers are used in audio systems to increase the volume of sound signals. They are commonly found in speakers, headphones, and audio amplifiers.
2. Telecommunications: Amplifiers are used in telecommunication systems to boost the strength of weak signals for transmission over long distances.
3. Medical Devices: Amplifiers are used in medical devices such as electrocardiographs (ECGs), electroencephalographs (EEGs), and ultrasound machines to amplify and process biological signals.
4. Instrumentation: Amplifiers are used in scientific instruments and measuring devices to amplify weak electrical signals for accurate measurement and analysis.
In conclusion, amplification refers to the increase in voltage or power of an electrical signal. It plays a crucial role in various electronic devices and has numerous applications in different fields.
The bandwidth sufficient for commercial telephonic communication:- a)700 Hz
- b)2800 Hz
- c)1400 Hz
- d)300 Hz
Correct answer is option 'B'. Can you explain this answer?
The bandwidth sufficient for commercial telephonic communication:
a)
700 Hz
b)
2800 Hz
c)
1400 Hz
d)
300 Hz
|
Priya Patel answered |
For speech signals (as in telephone) frequency range 300 Hz- 3100 Hz is adequate i.e., a speech signal requires a bandwidth of 2800 Hz.
Attenuation of a signal is- a)unwanted signals that disturb the message signal
- b)Loss of strength of signal while propagating
- c)the lack of attention while transmitting signals
- d)attention that is paid while transmitting a signal
Correct answer is option 'B'. Can you explain this answer?
Attenuation of a signal is
a)
unwanted signals that disturb the message signal
b)
Loss of strength of signal while propagating
c)
the lack of attention while transmitting signals
d)
attention that is paid while transmitting a signal
|
|
Akshay Shah answered |
Attenuation is a general term that refers to any reduction in the strength of a signal. Attenuation occurs with any type of signal, whether digital or analog. Sometimes called loss, attenuation is a natural consequence of signal transmission over long distances.
A rectifier and an envelope detector for AM uses- a)opamps for rectification and zener diodes for storing the peaks
- b)diodes for rectification and capacitors for storing the peaks
- c)transistors for rectification and zener diodes for storing the peaks
- d)none of these
Correct answer is option 'B'. Can you explain this answer?
A rectifier and an envelope detector for AM uses
a)
opamps for rectification and zener diodes for storing the peaks
b)
diodes for rectification and capacitors for storing the peaks
c)
transistors for rectification and zener diodes for storing the peaks
d)
none of these
|
Amar Shah answered |
Rectifier and Envelope Detector for AM
Rectification and envelope detection are the basic functions of an AM receiver. Rectification is the process of converting the AC signal to DC, and envelope detection is the process of extracting the modulating signal from the amplitude modulated signal.
Diodes and Capacitors for Rectification and Envelope Detection
The most commonly used components for rectification and envelope detection are diodes and capacitors. The diodes are connected in series with the signal, and they allow only the positive half cycles of the signal to pass while blocking the negative half cycles. The output of the diode is a pulsating DC signal.
The capacitor is connected across the output of the diode, and it filters out the high-frequency components of the pulsating DC signal, leaving only the low-frequency modulating signal. The output of the capacitor is the envelope of the AM signal.
Advantages of Diodes and Capacitors
The diodes and capacitors are simple and inexpensive components that are readily available. They are also highly reliable and have a long operating life. Moreover, they are easy to use and require no external power source.
Conclusion
In conclusion, diodes and capacitors are the preferred components for rectification and envelope detection in an AM receiver. They provide a simple and reliable solution for extracting the modulating signal from the amplitude modulated carrier signal.
Rectification and envelope detection are the basic functions of an AM receiver. Rectification is the process of converting the AC signal to DC, and envelope detection is the process of extracting the modulating signal from the amplitude modulated signal.
Diodes and Capacitors for Rectification and Envelope Detection
The most commonly used components for rectification and envelope detection are diodes and capacitors. The diodes are connected in series with the signal, and they allow only the positive half cycles of the signal to pass while blocking the negative half cycles. The output of the diode is a pulsating DC signal.
The capacitor is connected across the output of the diode, and it filters out the high-frequency components of the pulsating DC signal, leaving only the low-frequency modulating signal. The output of the capacitor is the envelope of the AM signal.
Advantages of Diodes and Capacitors
The diodes and capacitors are simple and inexpensive components that are readily available. They are also highly reliable and have a long operating life. Moreover, they are easy to use and require no external power source.
Conclusion
In conclusion, diodes and capacitors are the preferred components for rectification and envelope detection in an AM receiver. They provide a simple and reliable solution for extracting the modulating signal from the amplitude modulated carrier signal.
In ground wave propagation the earth- a)reflects the waves
- b)none of these
- c)amplifies the radiated signal
- d)attenuates the radiated signal as a result of energy absorption by it
Correct answer is option 'D'. Can you explain this answer?
In ground wave propagation the earth
a)
reflects the waves
b)
none of these
c)
amplifies the radiated signal
d)
attenuates the radiated signal as a result of energy absorption by it
|
|
Aarya Khanna answered |
Ground wave propagation refers to the transmission of radio waves along the surface of the Earth. In this mode of propagation, the Earth plays a significant role in the behavior of the waves. Among the options given, option D is the correct answer, which states that the Earth attenuates the radiated signal as a result of energy absorption.
Explanation:
1. Nature of ground wave propagation:
- Ground waves are characterized by low-frequency signals, typically below 2 MHz, and are often used for long-distance communication.
- These waves follow the curvature of the Earth and travel along the Earth's surface.
2. Attenuation of the radiated signal:
- As the ground wave propagates, it interacts with the Earth's surface, causing a gradual decrease in signal strength.
- This attenuation occurs due to the absorption of energy by the Earth.
- The ground acts as a lossy medium, absorbing a portion of the energy carried by the wave.
- This absorption leads to a decrease in the amplitude of the wave as it travels.
3. Factors affecting attenuation:
- The amount of attenuation depends on various factors, such as the frequency of the signal and the type of ground.
- Higher frequencies experience more attenuation due to increased absorption by the Earth.
- Different types of soil and terrain can also affect the attenuation, with moist soil and conductive surfaces causing more absorption.
4. Effects on communication:
- The attenuation of the ground wave signal limits its range, as the signal strength decreases with distance.
- This mode of propagation is suitable for medium-range communication, typically within a few hundred kilometers.
- Beyond a certain distance, the signal becomes too weak to be received reliably.
- To overcome the limitations of ground wave propagation, other modes such as skywave or spacewave propagation are used for long-distance communication.
In conclusion, ground wave propagation is characterized by the attenuation of the radiated signal as a result of energy absorption by the Earth. This phenomenon limits the range of ground wave communication and necessitates the use of other propagation modes for long-distance communication.
Explanation:
1. Nature of ground wave propagation:
- Ground waves are characterized by low-frequency signals, typically below 2 MHz, and are often used for long-distance communication.
- These waves follow the curvature of the Earth and travel along the Earth's surface.
2. Attenuation of the radiated signal:
- As the ground wave propagates, it interacts with the Earth's surface, causing a gradual decrease in signal strength.
- This attenuation occurs due to the absorption of energy by the Earth.
- The ground acts as a lossy medium, absorbing a portion of the energy carried by the wave.
- This absorption leads to a decrease in the amplitude of the wave as it travels.
3. Factors affecting attenuation:
- The amount of attenuation depends on various factors, such as the frequency of the signal and the type of ground.
- Higher frequencies experience more attenuation due to increased absorption by the Earth.
- Different types of soil and terrain can also affect the attenuation, with moist soil and conductive surfaces causing more absorption.
4. Effects on communication:
- The attenuation of the ground wave signal limits its range, as the signal strength decreases with distance.
- This mode of propagation is suitable for medium-range communication, typically within a few hundred kilometers.
- Beyond a certain distance, the signal becomes too weak to be received reliably.
- To overcome the limitations of ground wave propagation, other modes such as skywave or spacewave propagation are used for long-distance communication.
In conclusion, ground wave propagation is characterized by the attenuation of the radiated signal as a result of energy absorption by the Earth. This phenomenon limits the range of ground wave communication and necessitates the use of other propagation modes for long-distance communication.
Which of these is an example of broadcast communication?- a)Radio
- b)Mobile
- c)Telephony
- d)FAX
Correct answer is option 'A'. Can you explain this answer?
Which of these is an example of broadcast communication?
a)
Radio
b)
Mobile
c)
Telephony
d)
FAX
|
|
Sravya Datta answered |
Explanation:In broadcast mode of communication a large number of receivers are linked to a single transmiiter.Radio works as receiver which converts the transmiited information/message into the original form of the information.
The three elements of a generalized communication system are- a)Transmitter, transmission channel and receiver
- b)Transmitter, transmission channel and detector
- c)Transmitter, noise generator and receiver
- d)Transmitter, multiplier and receiver
Correct answer is option 'A'. Can you explain this answer?
The three elements of a generalized communication system are
a)
Transmitter, transmission channel and receiver
b)
Transmitter, transmission channel and detector
c)
Transmitter, noise generator and receiver
d)
Transmitter, multiplier and receiver
|
Pragati Choudhury answered |
Explanation:In communication the Transmitter helps in transmitting the signal through communication channel which acts as a physical path that connects transmitter to a receiver.And the receiver receives the transmitted signal and converts those signals in their original form.
Which of these is an example of point to point communication?- a)AM Radio
- b)Telephony
- c)TV
- d)FM Radio
Correct answer is option 'B'. Can you explain this answer?
Which of these is an example of point to point communication?
a)
AM Radio
b)
Telephony
c)
TV
d)
FM Radio
|
Anjana Sen answered |
Explanation:In point to point communication,communication occurs over a link between a single transmitter and receiver.Telephony is an example of it as it needs a link between caller and receiver to transmit the information.This link is provided by various media like cable.
Transmission bandwidth of fiber optic communication can be up to- a)100 Hz
- b)110 kHz
- c)416 MHz
- d)100 GHz
Correct answer is option 'D'. Can you explain this answer?
Transmission bandwidth of fiber optic communication can be up to
a)
100 Hz
b)
110 kHz
c)
416 MHz
d)
100 GHz
|
|
Aarya Khanna answered |
Transmission bandwidth of fiber optic communication can be up to 100 GHz.
Fiber optic communication is a method of transmitting information from one location to another by sending pulses of light through an optical fiber. This technology is widely used in telecommunications, internet connectivity, and data transmission due to its high-speed and high-capacity capabilities.
What is transmission bandwidth?
Transmission bandwidth refers to the range of frequencies that can be transmitted through a communication channel. It represents the amount of data that can be transmitted per unit of time and is usually measured in hertz (Hz) or gigahertz (GHz).
Fiber optic communication and its bandwidth
Fiber optic communication offers a much higher bandwidth compared to traditional copper-based communication systems. This is primarily due to the characteristics of light transmission through optical fibers.
1. Fiber optic cables and light transmission
Fiber optic cables consist of a core, which is a thin strand of glass or plastic, surrounded by a cladding material that reflects light back into the core. Light signals are transmitted through the core of the optical fiber using total internal reflection.
2. Advantages of fiber optic communication
- High bandwidth: Fiber optic cables can transmit a wide range of frequencies, allowing for high-speed data transmission. This is because light signals can operate at very high frequencies.
- Low signal loss: Optical fibers have much lower signal loss compared to copper cables, allowing for longer transmission distances without the need for repeaters.
- Immunity to electromagnetic interference: Fiber optic cables are not affected by electromagnetic interference, making them suitable for use in environments with high electromagnetic noise.
- Security: Since fiber optic cables transmit light signals, they are difficult to tap into, providing a higher level of security compared to copper cables.
3. Transmission bandwidth of fiber optic communication
The transmission bandwidth of fiber optic communication can be up to 100 GHz. This means that fiber optic cables are capable of transmitting a wide range of frequencies up to 100 GHz. This high bandwidth allows for the transmission of large amounts of data over long distances at very high speeds.
In conclusion
Fiber optic communication offers a high transmission bandwidth of up to 100 GHz, making it a preferred choice for high-speed data transmission. The use of optical fibers and light signals allows for efficient and secure communication with low signal loss and immunity to electromagnetic interference.
Fiber optic communication is a method of transmitting information from one location to another by sending pulses of light through an optical fiber. This technology is widely used in telecommunications, internet connectivity, and data transmission due to its high-speed and high-capacity capabilities.
What is transmission bandwidth?
Transmission bandwidth refers to the range of frequencies that can be transmitted through a communication channel. It represents the amount of data that can be transmitted per unit of time and is usually measured in hertz (Hz) or gigahertz (GHz).
Fiber optic communication and its bandwidth
Fiber optic communication offers a much higher bandwidth compared to traditional copper-based communication systems. This is primarily due to the characteristics of light transmission through optical fibers.
1. Fiber optic cables and light transmission
Fiber optic cables consist of a core, which is a thin strand of glass or plastic, surrounded by a cladding material that reflects light back into the core. Light signals are transmitted through the core of the optical fiber using total internal reflection.
2. Advantages of fiber optic communication
- High bandwidth: Fiber optic cables can transmit a wide range of frequencies, allowing for high-speed data transmission. This is because light signals can operate at very high frequencies.
- Low signal loss: Optical fibers have much lower signal loss compared to copper cables, allowing for longer transmission distances without the need for repeaters.
- Immunity to electromagnetic interference: Fiber optic cables are not affected by electromagnetic interference, making them suitable for use in environments with high electromagnetic noise.
- Security: Since fiber optic cables transmit light signals, they are difficult to tap into, providing a higher level of security compared to copper cables.
3. Transmission bandwidth of fiber optic communication
The transmission bandwidth of fiber optic communication can be up to 100 GHz. This means that fiber optic cables are capable of transmitting a wide range of frequencies up to 100 GHz. This high bandwidth allows for the transmission of large amounts of data over long distances at very high speeds.
In conclusion
Fiber optic communication offers a high transmission bandwidth of up to 100 GHz, making it a preferred choice for high-speed data transmission. The use of optical fibers and light signals allows for efficient and secure communication with low signal loss and immunity to electromagnetic interference.
Transducer is a device that- a)converts non electrical signals to electrical signals
- b)converts electrical signals to non electrical signals
- c)converts low power to high power
- d)converts high power to low power
Correct answer is option 'A'. Can you explain this answer?
Transducer is a device that
a)
converts non electrical signals to electrical signals
b)
converts electrical signals to non electrical signals
c)
converts low power to high power
d)
converts high power to low power
|
Asha Nair answered |
Explanation:Any device which converts energy from one form to another is called a transducer.It converts variation in physical quantities such as pressure,dispalcement,force,temprature etc.Like microphone converts sound signal into an electrical signal.
Range of an electronic communication system- a)distance to the nearest TV station
- b)distance to the nearest Radio station
- c)is the largest distance between a source and a destination up to which the signal is received with sufficient strength.
- d)is the largest distance the signal can travel
Correct answer is option 'C'. Can you explain this answer?
Range of an electronic communication system
a)
distance to the nearest TV station
b)
distance to the nearest Radio station
c)
is the largest distance between a source and a destination up to which the signal is received with sufficient strength.
d)
is the largest distance the signal can travel
|
|
Pragati Choudhury answered |
Explanation:As the distance between the source and the destination increases the strenght of the transmitted signals become weaker and weaker and the distance where it loses energy to travel any more is range of the signal.
Frequencies in the UHF range normally propagate by means of:- a)Ground waves.
- b)Space waves
- c)Surface waves.
- d)Sky waves
Correct answer is option 'B'. Can you explain this answer?
Frequencies in the UHF range normally propagate by means of:
a)
Ground waves.
b)
Space waves
c)
Surface waves.
d)
Sky waves
|
|
Hitakshi Tamta answered |
Owing to its high frequency, an ultra high frequency (UHF) wave can neither travel along the trajectory of the ground nor can it get reflected by the ionosphere. The signals having UHF are propagated through line-of-sight communication, which is nothing but "space wave" propagation. So, option 'B' is correct.
In Amplitude modulation if one of the two side bands is removed by a filter is it possible to recover the modulating signal?- a)Yes if signal is weak
- b)Yes
- c)No
- d)No if the signal is strong
Correct answer is option 'B'. Can you explain this answer?
In Amplitude modulation if one of the two side bands is removed by a filter is it possible to recover the modulating signal?
a)
Yes if signal is weak
b)
Yes
c)
No
d)
No if the signal is strong
|
Rajesh Chauhan answered |
Answer:
Introduction:
Amplitude Modulation (AM) is a type of modulation in which the amplitude of a high-frequency carrier wave is varied in accordance with the amplitude of the modulating signal.
Recovering the modulating signal:
If one of the two sidebands is removed by a filter, it is still possible to recover the modulating signal by using a demodulator circuit. This is because the modulating signal is contained in both the upper and lower sidebands, and even if one of the sidebands is removed, the other sideband still contains enough information to recover the original modulating signal.
Importance of signal strength:
The strength of the signal does not affect the ability to recover the modulating signal. Whether the signal is weak or strong, the modulating signal can still be recovered as long as one of the sidebands is present.
Conclusion:
Therefore, we can conclude that if one of the two sidebands is removed by a filter, it is still possible to recover the modulating signal, regardless of the strength of the signal.
Introduction:
Amplitude Modulation (AM) is a type of modulation in which the amplitude of a high-frequency carrier wave is varied in accordance with the amplitude of the modulating signal.
Recovering the modulating signal:
If one of the two sidebands is removed by a filter, it is still possible to recover the modulating signal by using a demodulator circuit. This is because the modulating signal is contained in both the upper and lower sidebands, and even if one of the sidebands is removed, the other sideband still contains enough information to recover the original modulating signal.
Importance of signal strength:
The strength of the signal does not affect the ability to recover the modulating signal. Whether the signal is weak or strong, the modulating signal can still be recovered as long as one of the sidebands is present.
Conclusion:
Therefore, we can conclude that if one of the two sidebands is removed by a filter, it is still possible to recover the modulating signal, regardless of the strength of the signal.
Chapter doubts & questions for Communication Systems - Physics CUET UG Mock Test Series 2025 2025 is part of JEE exam preparation. The chapters have been prepared according to the JEE exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for JEE 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.
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