Description : What noise type is observable between 8 MHz to somewhat above 1.43 GHz or up to 1.5 GHz? A. Solar noise B. Space noise C. Galactic noise D. Cosmic noise
Last Answer : B. Space noise
Description : Atmospheric noise is known as _______noise. A. static B. cosmic C. solar D. lunar
Last Answer : A. static
Description : A noise whose source is within the solar system. A. Solar noise B. Thermal noise C. Cosmic noise D. Johnson Noise
Last Answer : A. Solar noise
Description : _________ is measured on a circuit when it is correctly terminated but does not have any traffic. A. White noise B. Galactic noise C. Impulse noise D. Atmospheric noise
Last Answer : A. White noise
Description : External noise originating outside the solar system A. Cosmic noise B. Solar noise C. Thermal noise D. Lunar noise
Last Answer : A. Cosmic noise
Description : A large emission of hydrogen from the sun that affects communications. A. Solar flare B. Cosmic disturbance C. Ballistic disturbance D. Solar noise
Last Answer : A. Solar flare
Description : What do you call the noise coming from the sun and stars? A. Black-body noise B. Space noise C. Galactic noise D. All of these
Description : Form of interference caused by rain or dust storms. A. Precipitation static B. Shot-noise C. Galactic noise D. Impulse noise
Last Answer : A. Precipitation static
Description : Distances of stars are measured in – (1) Galactic unit (2) Stellar mile (3) Cosmic kilometre (4) Light year
Last Answer : (4) Light year Explanation: Light year is a unit of length used informally to express astronomical distances. It is most often used when expressing distances to stars and other distances on a galactic scale. It is equal to just under 10 trillion kilometres.
Description : Distances of stars are measured in (1) Galactic unit (2) Stellar mile (3) Cosmic kilometre (4) Light year
Last Answer : Light year
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
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
Description : Indicate the false statement. A. HF mixer are generally noisier than HF amplifiers. B. Impulse noise voltage is dependent on bandwidth C. Thermal noise is independent of the frequency at which is measured. D. Industrial noise is usually of the impulse type.
Last Answer : B. Impulse noise voltage is dependent on bandwidth
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
Description : The major cause of atmospheric or static noise are A. Thunderstorms B. Airplanes C. Meteor showers D. All of these
Last Answer : A. Thunderstorms
Description : What is the primary cause of atmospheric noise? A. Thunderstorm B. Lightning C. Thunderstorm and lightning D. Weather condition
Last Answer : B. Lightning
Description : Atmospheric noise becomes less severe at frequencies A. above 30 MHz B. below 30 MHz C. above 3000 kHz D. below 3000kHz
Last Answer : A. above 30 MHz
Description : Atmospheric noise or static is not a great problem A. at frequencies below 20 MHz B. at frequencies below 5 MHz C. at frequencies above 30 MHz D. at frequencies above 1 MHz
Last Answer : C. at frequencies above 30 MHz
Description : Which noise is produced by lighting discharges in thunderstorms? A. White noise B. Extraterrestrial noise C. Industrial noise D. Atmospheric noise
Last Answer : D. Atmospheric noise
Description : What do you call the random noise seen on radar display screen? A. Impulse noise B. Atmospheric noise C. Grass D. Johnson noise
Last Answer : C. Grass
Description : What noise is observable at frequencies in the range from about 8 MHz to somewhat 1.5 GHz? A. Industrial noise B. Atmospheric noise C. Space noise D. Shot noise
Last Answer : C. Space noise
Description : The band of frequencies least susceptible to atmospheric noise and interference is: A. 30 – 300 kHz B. 300 – 3000 kHz C. 3 – 30 MHz D. 300 – 3000 MHz
Last Answer : D. 300 – 3000 MHz
Description : What is the major cause of atmospheric or static noise? A. Sunspots B. Airplanes C. Meteor showers D. Thunderstorm
Last Answer : D. Thunderstorm
Description : Atmospheric noise is less at severe frequencies above A. Audio level B. 30 MHz C. 10 GHz D. 1 GHz
Last Answer : B. 30 MHz
Description : Sources of impulse noise induced in communication channels. A. Erroneous digital coding bit caused by an error on a transmission facility B. Transients due to relay operation C. Crosstalk from dc signaling systems D. All of these
Last Answer : D. All of these
Description : Name one or more sources of noise bearing on electronic communications. A. Steam boiler B. Galaxies C. Internal combustion engine D. Both B and C
Last Answer : D. Both B and C
Description : The main power sources for a satellite are A. batteries B. solar cells C. fuel cells D. thermoelectric generators 58. The maximum height of an ellip
Last Answer : B. solar cells
Description : An advantage of optic fiber rejecting an induced noise signals from magnetic field or solar storms flux. A. Electric hazard B. Cross talk C. Immunity to noise D. Shielding
Last Answer : C. Immunity to noise
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
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
Description : Calculated the noise figure of the amplifier whose Req equals 2518Ω (RT=600Ω) if its driven by a generator whose output impedance is 50Ω. A. 39.4 B. 3.94 C. 394 D. 0.394
Last Answer : A. 39.4
Description : The front-end of a television receiver, having a bandwidth of 7Mhz, and operating at a temperature of 27˚C , consists of an amplifier having a gain of 15 followed by a mixer whose gain is 20. The ... equivalent noise resistance for this television receiver. A. 8760 Ω B. 875Ω C. 8.76Ω D. 0.876Ω
Last Answer : B. 875Ω
Description : _______ is more prevalent in analog signals that have steep slopes or whose amplitudes vary rapidly. A. Peak limiting B. Quantization noise C. Granular noise D. Slope overload
Last Answer : D. Slope overload
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
Description : Thunderstorms, snowstorms, cosmic sources, the sun, etc., are a few examples of emi sources. What type of emi comes
Last Answer : Natural.
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
Description : Consider the following statements: 1. The atmosphere of the primitive earth was reducing 2. The primary source of energy for the chemosynthetic reactions on earth that led to the origin of life was the solar energy 3. Liquid water did not ... 1 and 2 (b) 1 and 4 (c) 1, 2, and 3 (d) 1, 3, and 4
Last Answer : Ans:(d)
Description : It is dangerous to observe solar eclipse with naked eyes because – (1) Infrared radiations from sun burn our retina (2) Ultraviolet radiations from Sun burn our retina (3) All radiations from sun initiate chemical reactions in eyes (4) Cosmic rays reach eyes more during the eclipse
Last Answer : (2) Ultraviolet radiations from Sun burn our retina Explanation: The solar radiation that reaches the surface of Earth ranges from ultraviolet (UV) radiation at wavelengths longer than 290 nm to radio ... of the Sun during an eclipse is for the development of "eclipse blindness" or retinal burns.
Description : Which of the following parts of the sunlight makes the solar cooker hot? (1) Ultra violet (2) Red light (3) Infra red (4) Cosmic rays
Last Answer : (3) Infra red Explanation: Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect. A solar cooker, or solar oven, is a device which ... The vast majority of the solar cookers presently in use are relatively cheap, low-tech devices.
Description : It is dangerous to observe Solar eclipse with naked eyes because (1) Infrared radiations from sun burn our retina (2) Ultraviolet radiations from Sun burn our retina (3) All radiations from sun initiate chemical reactions in eyes (4) Cosmic rays reach eyes more during the eclipse
Last Answer : Ultraviolet radiations from Sun burn our retina
Description : Which of the following parts of the sunlight makes the solar cooker hot ? (1) Ultra violet (2) Red light (3) Infra red (4) Cosmic rays
Last Answer : Infra red
Description : Which is atmospheric attenuation? A. Attenuation due to rain B. Attenuation due to other gasses C. Attenuation due to mist and fog D. Due to water vapor and oxygen
Last Answer : D. Due to water vapor and oxygen
Description : Indicate which of the following reasons for using metal counterpoise with antennas is false. A. Impossibly of a good ground connection B. Protection of personnel working underneath C. Provision of an earth for the antenna D. Rockiness of the ground itself
Last Answer : B. Protection of personnel working underneath
Description : What is the proper procedure for suppressing electrical noise in a mobile station? A. Apply shielding and filtering where necessary B. Insulate a all plain sheet metal surfaces from each other C. ... -static spray liberally to all nonmetallic D. Install filter capacitors in series with all dc wiring
Last Answer : A. Apply shielding and filtering where necessary
Description : What does the noise weighting curve shows? A. Noise signals measured with a 144 handset B. Power levels of noise found in carrier systems C. The interfering effect of other frequencies in a voice ... a reference frequency of one kilohertz D. Interfering effects of signals compared with a 3-kHz tone
Last Answer : C. The interfering effect of other frequencies in a voice channel compared with a reference frequency of one kilohertz
Description : In Excel chart, text displayed at data points to indicate the specific category is called …………….. -Technology
Last Answer : (c) Text displayed at data points to indicate the specific category is called data label.
Description : Which of the following factor does not harm laser efficiency? a. Atmospheric absorption b. Excitation energy not absorbed c. Problems in depopulating the lower laser level d. Inefficiency in populating the upper laser level
Last Answer : a. Atmospheric absorption
Description : Is a loss of power of a satellite downlink signal due to earth’s atmosphere. A. Atmospheric loss B. Path loss C. Radiation loss D. RFI
Last Answer : B. Path loss
Description : Atmospheric attenuation is an attenuation which is due to A. mist and fog B. gasses in the atmosphere C. water vapor and oxygen D. rain
Last Answer : C. water vapor and oxygen