In case of low level amplitude modulation system, the amplifiers following the modulated stage must be
In case of low level amplitude modulation system, the amplifiers following the modulated stage must be
Circular polarization
Circular polarization
Leak type bias is used in plate modulated class C amplifier to
Leak type bias is used in plate modulated class C amplifier to
Which one of the following is analog?
Which one of the following is analog?
The maximum power output of a standard A earth station over the total band allocated to satellite communication is about
The maximum power output of a standard A earth station over the total band allocated to satellite communication is about
The main function of a balanced modulator is to
The main function of a balanced modulator is to
A buffer amplifier is
A buffer amplifier is
One of the advantages of base modulation over collector modulation of a transistor class C amplifier is
One of the advantages of base modulation over collector modulation of a transistor class C amplifier is
SSB can be generated by
SSB can be generated by
Full duplex operation permits transmission in both directions at the same time.
Full duplex operation permits transmission in both directions at the same time.
If in a broadcasting studio, a 1000 kHz carrier is modulated by an audio signal of frequency range 100-5000 kHz, the width of channel is __________ kHz.
If in a broadcasting studio, a 1000 kHz carrier is modulated by an audio signal of frequency range 100-5000 kHz, the width of channel is __________ kHz.
When the length of antenna is a whole wavelength
When the length of antenna is a whole wavelength
In practical commercial FM system, channel bandwidth is
In practical commercial FM system, channel bandwidth is
The disadvantage of FM over AM is that
The disadvantage of FM over AM is that
An FM radio receiver which is tuned to a 91.6 MHz broadcast station may receive an image frequency of __________ MHz.
An FM radio receiver which is tuned to a 91.6 MHz broadcast station may receive an image frequency of __________ MHz.
For AM receivers the standard IF frequency is
For AM receivers the standard IF frequency is
In Pulse Code Modulation system
In Pulse Code Modulation system
Which of the following is a digital modulation technique?
Which of the following is a digital modulation technique?
A three stage telephone switching structure is to have 128 input and 128 output terminals. There are 16 first stage and 16 third stage matrices. To avoid blocking the number of intermediate paths required is
A three stage telephone switching structure is to have 128 input and 128 output terminals. There are 16 first stage and 16 third stage matrices. To avoid blocking the number of intermediate paths required is
To eliminate ghosts in the picture
To eliminate ghosts in the picture
PAM stands for
PAM stands for
Under ordinary circumstances, impulse noise can be reduced in
Under ordinary circumstances, impulse noise can be reduced in
In case of frequency modulation, modulating voltage remains constant if the modulating frequency is lowered, then
In case of frequency modulation, modulating voltage remains constant if the modulating frequency is lowered, then
If output power of a radio receiver is doubled, its volume is increased by __________ dB.
If output power of a radio receiver is doubled, its volume is increased by __________ dB.
For a given carrier wave, maximum undistorted power is transmitted when value of modulation is
For a given carrier wave, maximum undistorted power is transmitted when value of modulation is
As per Shannon-Hartley theorem, a noise less Gaussian channel has
As per Shannon-Hartley theorem, a noise less Gaussian channel has
Which of the following does not cause losses in optical fibre cables?
Which of the following does not cause losses in optical fibre cables?
The colour of an object is decided by
The colour of an object is decided by
In a FM receiver, amplitude limiter
In a FM receiver, amplitude limiter
Which of the following is used to generate PDM?
Which of the following is used to generate PDM?
A modem is classified as low speed if data rate handled is
A modem is classified as low speed if data rate handled is
In a TV receiver antenna the length of reflector rod
In a TV receiver antenna the length of reflector rod
A zero mean white Gaussian noise is passed through an ideal low pass filter of bandwidth 10 kHz. The output of the samples so obtained would be
A zero mean white Gaussian noise is passed through an ideal low pass filter of bandwidth 10 kHz. The output of the samples so obtained would be
A woofer should be fed from the input through a
A woofer should be fed from the input through a
Commercial Frequency deviation of FM is
Commercial Frequency deviation of FM is
What is the purpose of peak clipper circuits in radio transmitters?
What is the purpose of peak clipper circuits in radio transmitters?
For telegraphy the most commonly used modulation system is
For telegraphy the most commonly used modulation system is
Skip distance depends on time of day and angle of incidence.
Skip distance depends on time of day and angle of incidence.
Fourier analysis indicate that a square wave can be represented as
Fourier analysis indicate that a square wave can be represented as
Which of the following is an indirect way of generating FM?
Which of the following is an indirect way of generating FM?
A cordless telephone using separate frequencies for transmission in base and portable units is known as
A cordless telephone using separate frequencies for transmission in base and portable units is known as
The direction of rotation of a CD is
The direction of rotation of a CD is
If sampling is done at the rate of 10 kHz. The bandwidth required is
If sampling is done at the rate of 10 kHz. The bandwidth required is
For attenuation of high frequencies we should use
For attenuation of high frequencies we should use
An audio signal (say from 50 Hz to 10000 Hz) is frequency translated by a carrier having a frequency of 106 Hz. The values of initial (without frequency translation) and final (after frequency translation) fractional change in frequency from one band edge to the other are
An audio signal (say from 50 Hz to 10000 Hz) is frequency translated by a carrier having a frequency of 106 Hz. The values of initial (without frequency translation) and final (after frequency translation) fractional change in frequency from one band edge to the other are
For a low level AM system, the amplifiers modulated stage must be
For a low level AM system, the amplifiers modulated stage must be
It is found that a ship to ship communication suffers from fading. This can be avoided by using
It is found that a ship to ship communication suffers from fading. This can be avoided by using
For a plate-modulated class C amplifier the plate supply voltage is E. The maximum plate cathode voltage could be almost high as
For a plate-modulated class C amplifier the plate supply voltage is E. The maximum plate cathode voltage could be almost high as
Assertion (A): In FM the frequency of the carrier is varied by the modulating voltage
Reason (R): FM and PM are two forms of angle modulation.
Assertion (A): In FM the frequency of the carrier is varied by the modulating voltage
Reason (R): FM and PM are two forms of angle modulation.
FM transmitting and receiving equipment as compared to AM equipment is
FM transmitting and receiving equipment as compared to AM equipment is
In Modulation, “carrier” is
In Modulation, “carrier” is
A telephone channel requires a bandwidth of about
A telephone channel requires a bandwidth of about
In TV systems, equalising pulses are sent during
In TV systems, equalising pulses are sent during
The modulation index of an FM is changed from 0 to 1. How does the transmitted power change?
The modulation index of an FM is changed from 0 to 1. How does the transmitted power change?
The frequency range of 300 kHz to 3000 kHz is known as
The frequency range of 300 kHz to 3000 kHz is known as
The characteristic impedance of a twin wire feeder used for TV signals is about
The characteristic impedance of a twin wire feeder used for TV signals is about
VSB modulation is preferred in TV because
VSB modulation is preferred in TV because
In EM waves, polarization
In EM waves, polarization
