Where is the noise generated that primarily determines the signal-to-noise ratio in a VHF (150MHz) marine-band receiver? A. Man-made noise B. In the atmosphere C. In the receiver front end D. In the ionosphere

Where is the noise generated that primarily determines the signal-to-noise ratio in a VHF
(150MHz) marine-band receiver?
A. Man-made noise
B. In the atmosphere
C. In the receiver front end
D. In the ionosphere
by

1 Answer

Answer :

C. In the receiver front end
by

Related questions

Where is the noise generated that primarily determines the signal-to-noise ratio in a VHF (150 MHz) marine-band receiver? A. In the ionosphere B. In the receiver rear end C. In the receiver front end D. In the atmosphere

Description : Where is the noise generated that primarily determines the signal-to-noise ratio in a VHF (150 MHz) marine-band receiver? A. In the ionosphere B. In the receiver rear end C. In the receiver front end D. In the atmosphere

Last Answer : C. In the receiver front end

What consists the front-end circuit of a VHF TV superheterodyne receiver? A. Mixer, RF amplifier and AFC? B. RF amplifier, Band pass filter and mixer C. Local oscillator, mixer and RF amplifier D. Local oscillator, AGC and antenna

Description : What consists the front-end circuit of a VHF TV superheterodyne receiver? A. Mixer, RF amplifier and AFC? B. RF amplifier, Band pass filter and mixer C. Local oscillator, mixer and RF amplifier D. Local oscillator, AGC and antenna

Last Answer : C. Local oscillator, mixer and RF amplifier

Refers to one of the front end circuit of a VHF TV superheterodyne receiver which is usually a separate circuit coupled to the mixer. A. Antenna feed B. AGC C. RF amplifier D. Local oscillator

Description : Refers to one of the front end circuit of a VHF TV superheterodyne receiver which is usually a separate circuit coupled to the mixer. A. Antenna feed B. AGC C. RF amplifier D. Local oscillator

Last Answer : D. Local oscillator

What causes image interference? A. Low gain B. High IF C. Poor front-end selectivity D. Low signal-to-noise ratio

Description : What causes image interference? A. Low gain B. High IF C. Poor front-end selectivity D. Low signal-to-noise ratio

Last Answer : C. Poor front-end selectivity

Indicate the false statement. Noise figure is defined as A. the ratio of the S/N power supplied at the input terminal of a receiver or amplifier to the S/N power supplied to the output or load resistor B. noise factor expressed in decibels C. an unwanted form of energy tending to interfere with the proper and easy reception and reproduction of wanted signal D. S/N of an ideal system divided by S/N at the output of the receiver or amplifier under test, both working at the same temperature over the same bandwidth and fed from the same source

Description : Indicate the false statement. Noise figure is defined as A. the ratio of the S/N power supplied at the input terminal of a receiver or amplifier to the S/N power supplied to the output or ... under test, both working at the same temperature over the same bandwidth and fed from the same source

Last Answer : C. an unwanted form of energy tending to interfere with the proper and easy reception and reproduction of wanted signals

Deemphasis in the receiver in effect attenuates modulating signal components and noise in what frequency range? A. dc B. low C. intermediate D. high

Description : Deemphasis in the receiver in effect attenuates modulating signal components and noise in what frequency range? A. dc B. low C. intermediate D. high

Last Answer : D. high

When no signal is being received, the loudspeaker is not entirely silent as a result of the presence of A. parasitic oscillations in some of the receiver stages. B. negative feedback in each stage. C. spurious frequencies as a result of improper neutralization. D. internal receiver noise.

Description : When no signal is being received, the loudspeaker is not entirely silent as a result of the presence of A. parasitic oscillations in some of the receiver stages. B. negative feedback in each stage. C. spurious frequencies as a result of improper neutralization. D. internal receiver noise.

Last Answer : D. internal receiver noise.

ECE Board Exam March 1996 What is the purpose of the receiver’s squelch circuit? A. To overcome fluctuations in the level the RF signal arriving at the receiver antenna B. To prevent fluctuations in the AGC bias level C. To reduce the receiver’s sensitivity to all incoming signals D. To prevent amplified noise from reaching the loudspeaker during the absence of an incoming signal

Description : ECE Board Exam March 1996 What is the purpose of the receiver's squelch circuit? A. To overcome fluctuations in the level the RF signal arriving at the receiver antenna B. To prevent ... signals D. To prevent amplified noise from reaching the loudspeaker during the absence of an incoming signal

Last Answer : D. To prevent amplified noise from reaching the loudspeaker during the absence of an incoming signal

What frequency band is referred to as the metric waves? A. VHF B. UHF C. HF D. SHF

Description : What frequency band is referred to as the metric waves? A. VHF B. UHF C. HF D. SHF

Last Answer : A. VHF

What is the metric subdivision of VHF band? A. Metric B. Millimetric C. Decimetric D. Centimetric

Description : What is the metric subdivision of VHF band? A. Metric B. Millimetric C. Decimetric D. Centimetric

Last Answer : A. Metric

Where does the AM broadcast band located in the spectrum band? A. HF band B. VHF band C. LF band D. MF band

Description : Where does the AM broadcast band located in the spectrum band? A. HF band B. VHF band C. LF band D. MF band

Last Answer : D. MF band

Which band does channel 14 of the television channel belong?A. High VHF band B. EHF band C. UHF band D. Low VHF band

Description : Which band does channel 14 of the television channel belong? A. High VHF band B. EHF band C. UHF band D. Low VHF band

Last Answer : C. UHF band

Channel 7 of the regular television channel belongs to which band? A. Low VHF band B. High VHF band C. Low UHF band D. High UHF band

Description : Channel 7 of the regular television channel belongs to which band? A. Low VHF band B. High VHF band C. Low UHF band D. High UHF band

Last Answer : B. High VHF band

TV channels 2, 4 and 5 are known as ________. A. Mid band UHF B. Low band UHF C. High band VHF D. Low band VHF

Description : TV channels 2, 4 and 5 are known as ________. A. Mid band UHF B. Low band UHF C. High band VHF D. Low band VHF

Last Answer : D. Low band VHF

Troposheric scatter uses the frequencies in the ________ band. A. VLF B. UHF C. VHF D. UF

Description : Troposheric scatter uses the frequencies in the ________ band. A. VLF B. UHF C. VHF D. UF

Last Answer : B. UHF

Which frequency band is the standard AM radio broadcast? A. HF B. UHF C. MF D. VHF

Description : Which frequency band is the standard AM radio broadcast? A. HF B. UHF C. MF D. VHF

Last Answer : C. MF

The rhombic antenna is primarily used for A. ground wave propagation B. space wave propagation C. ionosphere scatter propagation D. sky wave propagation

Description : The rhombic antenna is primarily used for A. ground wave propagation B. space wave propagation C. ionosphere scatter propagation D. sky wave propagation

Last Answer : D. sky wave propagation

What propagation condition is usually indicated when a VHF signal is received from a station over 500 miles away? A. D-layer absorption B. Faraday rotation C. Tropospheric ducting D. Moonbounce

Description : What propagation condition is usually indicated when a VHF signal is received from a station over 500 miles away? A. D-layer absorption B. Faraday rotation C. Tropospheric ducting D. Moonbounce

Last Answer : C. Tropospheric ducting

What propagation condition is usually indicated when a VHF signal is received from a station over 5000 miles away? A. Moonbounce B. D-layer absorption C. Tropospheric ducting D. Faraday rotation

Description : What propagation condition is usually indicated when a VHF signal is received from a station over 5000 miles away? A. Moonbounce B. D-layer absorption C. Tropospheric ducting D. Faraday rotation

Last Answer : C. Tropospheric ducting

What satellite system parameter represents the quality of a satellite or an earth station receiver? A. Gain-to-Equivalent Noise Temperature Ratio (G/Te) B. Energy of Bit-to-Noise Density Ratio (Eb/No) C. Carrier-to-Noise Density Ratio (C/No) D. Bit energy

Description : What satellite system parameter represents the quality of a satellite or an earth station receiver? A. Gain-to-Equivalent Noise Temperature Ratio (G/Te) B. Energy of Bit-to-Noise Density Ratio (Eb/No) C. Carrier-to-Noise Density Ratio (C/No) D. Bit energy

Last Answer : A. Gain-to-Equivalent Noise Temperature Ratio (G/Te)

Indicate the false statement. A. Industrial noise is usually of the impulse type B. Static is caused by lightning discharges in thunderstorms and other natural electric disturbances occurring in the atmosphere C. Distant stars are another source of man-made noise D. Flourescent lights are another source of man-made noise

Description : Indicate the false statement. A. Industrial noise is usually of the impulse type B. Static is caused by lightning discharges in thunderstorms and other natural electric disturbances occurring in the ... another source of man-made noise D. Flourescent lights are another source of man-made noise

Last Answer : C. Distant stars are another source of man-made noise

What causes the maximum usable frequency to vary? A. The temperature of the ionosphere B. The speed of the winds in the upper atmosphere C. The type of weather just below the ionosphere D. The amount of radiation received from the sun

Description : What causes the maximum usable frequency to vary? A. The temperature of the ionosphere B. The speed of the winds in the upper atmosphere C. The type of weather just below the ionosphere D. The amount of radiation received from the sun

Last Answer : D. The amount of radiation received from the sun

Stacking antenna elements A. increases sensitivity to weak signals B. will suppress odd harmonics C. decrease signal to noise ratio D. increases selectivity

Description : Stacking antenna elements A. increases sensitivity to weak signals B. will suppress odd harmonics C. decrease signal to noise ratio D. increases selectivity

Last Answer : A. increases sensitivity to weak signals

Three identical circuits having 10 dB signal noise-to-noise ratio each are connected in tandem with each other, what is the overall S/N? A. 5.23 dB B. 14.77dB C. 30 dB D. 40 dB

Description : Three identical circuits having 10 dB signal noise-to-noise ratio each are connected in tandem with each other, what is the overall S/N? A. 5.23 dB B. 14.77dB C. 30 dB D. 40 dB

Last Answer : A. 5.23 dB

What signal-to-noise ratio is required for satisfactory television reception? A. 10 dB B. 30 dB C. 40 dB D. 20 dB

Description : What signal-to-noise ratio is required for satisfactory television reception? A. 10 dB B. 30 dB C. 40 dB D. 20 dB

Last Answer : C. 40 dB

What is the quantization signal-to-noise ratio if an 8-bit PCM code is used? A. 40 dB B. 50 dB C. 60 dB D. 65 dB

Description : What is the quantization signal-to-noise ratio if an 8-bit PCM code is used? A. 40 dB B. 50 dB C. 60 dB D. 65 dB

Last Answer : B. 50 dB

What bandwidth is needed to support a capacity of 128 kbps when the signal power to noise power ratio in decibels is 100? A. 19224 Hz B. 3853 Hz C. 19244 Hz D. 3583 Hz

Description : What bandwidth is needed to support a capacity of 128 kbps when the signal power to noise power ratio in decibels is 100? A. 19224 Hz B. 3853 Hz C. 19244 Hz D. 3583 Hz

Last Answer : B. 3853 Hz

What is meant by the term modulation index? A. The processor index. B. The ratio between the deviation of a frequency modulated signal and the modulating frequency. C. The FM signal-to-noise ratio. D. The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency.

Description : What is meant by the term modulation index? A. The processor index. B. The ratio between the deviation of a frequency modulated signal and the modulating frequency. C. The FM signal-to-noise ratio. D. The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency.

Last Answer : B. The ratio between the deviation of a frequency modulated signal and the modulating frequency.

The signal to noise ratio that is required for a satisfactory television reception. A. 30 dB B. 40 dB C. 10 dB D. 20 dB

Description : The signal to noise ratio that is required for a satisfactory television reception. A. 30 dB B. 40 dB C. 10 dB D. 20 dB

Last Answer : B. 40 dB

What signal-to-noise ratio is required for satisfactory telephone services? A. 50 dB B. 30 dB C. 40dB D. 20 dB

Description : What signal-to-noise ratio is required for satisfactory telephone services? A. 50 dB B. 30 dB C. 40dB D. 20 dB

Last Answer : A. 50 dB

The signal in a channel is measured to be 23 dB while noise in the same channel is measured to be 9 dB. The signal to noise ratio therefore is __________. A. 9/23 B. 23/9 C. 32 dB D. 14 dB

Description : The signal in a channel is measured to be 23 dB while noise in the same channel is measured to be 9 dB. The signal to noise ratio therefore is __________. A. 9/23 B. 23/9 C. 32 dB D. 14 dB

Last Answer : D. 14 dB

For navigation as well as marine and aeronautical communications and radar, ____ band is used. A. L B. K C. S D. J

Description : For navigation as well as marine and aeronautical communications and radar, ____ band is used. A. L B. K C. S D. J

Last Answer : A. L

Comparing the signal strength arriving at the driven element from the desired direction to the signal strength reaching the driver from the opposite direction. A. Directivity B. Sensitivity C. Beamwidth D. Front-to-back ratio

Description : Comparing the signal strength arriving at the driven element from the desired direction to the signal strength reaching the driver from the opposite direction. A. Directivity B. Sensitivity C. Beamwidth D. Front-to-back ratio

Last Answer : D. Front-to-back ratio

Which noise figure represents the lowest noise in receiver? A. 1.6 dB B. 2.1 dB C. 2.7 dB D. 3.4 dB

Description : Which noise figure represents the lowest noise in receiver? A. 1.6 dB B. 2.1 dB C. 2.7 dB D. 3.4 dB

Last Answer : A. 1.6 dB

Which circuit contributes most of the noise in a receiver? A. IF amplifier B. Demodulator C. AF amplifier D. Mixer

Description : Which circuit contributes most of the noise in a receiver? A. IF amplifier B. Demodulator C. AF amplifier D. Mixer

Last Answer : D. Mixer

Noise at the input to the receiver can be as high as several A. microvolts B. milivolts C. volts D. kilo volts

Description : Noise at the input to the receiver can be as high as several A. microvolts B. milivolts C. volts D. kilo volts

Last Answer : A. microvolts

A receiver connected to an antenna whose resistance is 50 Ω has an equivalent noise resistance of 30Ω. Calculate its equivalent noise temperature if the noise figure is equal to 1.6. A. 17.4 K B. 174K C. 1.74K D. 17K

Description : A receiver connected to an antenna whose resistance is 50 Ω has an equivalent noise resistance of 30Ω. Calculate its equivalent noise temperature if the noise figure is equal to 1.6. A. 17.4 K B. 174K C. 1.74K D. 17K

Last Answer : B. 174K

Calculate the noise figure of the receiver whose RF amplifier has an input resistance of 1000Ω and an equivalent shot-noise resistance of 2000Ω, a gain of 25 and load resistance of 125 kΩ. Given that the bandwidth is 1.0MHz and the temperature is 20˚C, and that the receiver is connected to an antenna with an impedance of 75Ω. A. 30.3 B. 3.03 C. 303 D. .303

Description : Calculate the noise figure of the receiver whose RF amplifier has an input resistance of 1000Ω and an equivalent shot-noise resistance of 2000Ω, a gain of 25 and load resistance of 125 kΩ. Given that the bandwidth is 1. ... to an antenna with an impedance of 75Ω. A. 30.3 B. 3.03 C. 303 D. .303

Last Answer : A. 30.3

What limits the sensitivity of a receiver? A. The power supply of the receiver B. The power output of a transmitter C. The noise floor of the receiver D. The distance between the transmitter and receiver

Description : What limits the sensitivity of a receiver? A. The power supply of the receiver B. The power output of a transmitter C. The noise floor of the receiver D. The distance between the transmitter and receiver

Last Answer : C. The noise floor of the receiver

Referred to as the stage in the radio receiver that contributes most of the noise. A. IF amplifier B. Supply stage C. Speaker D. Mixer

Description : Referred to as the stage in the radio receiver that contributes most of the noise. A. IF amplifier B. Supply stage C. Speaker D. Mixer

Last Answer : D. Mixer

What do you call the single booster installed on the antenna dish of satellite receiver? A. Low noise amplifier B. Single amplifier C. Noise amplifier D. Rectifier

Description : What do you call the single booster installed on the antenna dish of satellite receiver? A. Low noise amplifier B. Single amplifier C. Noise amplifier D. Rectifier

Last Answer : A. Low noise amplifier

What is the mixing process? A. Distortion caused by auroral propagation B. The combination of two signals to produce sum and difference frequencies. C. The elimination of noise in wideband receiver by phase differentiation D. The elimination of noise in a wideband receiver by phase comparison

Description : What is the mixing process? A. Distortion caused by auroral propagation B. The combination of two signals to produce sum and difference frequencies. C. The elimination of noise in wideband receiver by phase differentiation D. The elimination of noise in a wideband receiver by phase comparison

Last Answer : B. The combination of two signals to produce sum and difference frequencies.

ECE Board Exam March 1996 A receiver connected to an antenna whose resistance is 50 ohms has an equivalent noise resistance of 30 ohms. What is the receiver’s noise temperature? A. 754 K B. 464 K C. 174 K D. 293 K

Description : ECE Board Exam March 1996 A receiver connected to an antenna whose resistance is 50 ohms has an equivalent noise resistance of 30 ohms. What is the receiver’s noise temperature? A. 754 K B. 464 K C. 174 K D. 293 K

Last Answer : C. 174 K

The square of the thermal noise voltage generated by a resistor is proportional to A. its resistance B. its temperature C. the bandwidth over which it is measured D. All of the above

Description : The square of the thermal noise voltage generated by a resistor is proportional to A. its resistance B. its temperature C. the bandwidth over which it is measured D. All of the above

Last Answer : D. All of the above

The value of the resistor creating thermal noise is doubled. The noise power generated is therefore. A. halved B. quadrupled C. doubled D. unchanged

Description : The value of the resistor creating thermal noise is doubled. The noise power generated is therefore. A. halved B. quadrupled C. doubled D. unchanged

Last Answer : D. unchanged

Indicate the false statement A. The noise generated in a resistance or the resistive component of any impedance is random. B. Random noise power is proportional to the bandwidth over which is measured C. A random voltage across the resistor does not exist D. All formula referring to random noise are applicable only to the value of such noise.

Description : Indicate the false statement A. The noise generated in a resistance or the resistive component of any impedance is random. B. Random noise power is proportional to the bandwidth over which is measured ... exist D. All formula referring to random noise are applicable only to the value of such noise.

Last Answer : C. A random voltage across the resistor does not exist

At 17˚ C, the noise voltage generated by 5kΩ resistor, operating over a bandwidth of 20KHz is A. 1.3 nV B. 1.3 µV C. 1.3 pV D. 1.3 mV

Description : At 17˚ C, the noise voltage generated by 5kΩ resistor, operating over a bandwidth of 20KHz is A. 1.3 nV B. 1.3 µV C. 1.3 pV D. 1.3 mV

Last Answer : B. 1.3 µV

What determines the ability of radar to determine the bearing to a target? A. Speed of light B. Speed of target C. Antenna directivity D. Frequency of signal

Description : What determines the ability of radar to determine the bearing to a target? A. Speed of light B. Speed of target C. Antenna directivity D. Frequency of signal

Last Answer : C. Antenna directivity

Which of the following refers to the video signal amplitude that determines the quality of the picture? A. Chrominance B. Luminance C. Brightness D. Contrast

Description : Which of the following refers to the video signal amplitude that determines the quality of the picture? A. Chrominance B. Luminance C. Brightness D. Contrast

Last Answer : D. Contrast