Description : What condition occur when the refractive index of the air decreases with height much more rapidly the normal? A. Refraction B. Superrefraction C. Subrefraction D. Diffraction
Last Answer : B. Superrefraction
Description : ____ is a term given to the region where superrefraction occurs. A. Strata B. Duct C. Isothermal region D. Tropospheric region
Last Answer : B. Duct
Description : What phenomenon causes the radio-path horizon distance to exceed the geometric horizon? A. Diffraction B. Ducting C. Reflection D. Refraction
Last Answer : D. Refraction
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
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
Description : This type of transmission permits communication in the frequency range from 30 to 60 MHz and over distances from about 1000 to 2000 km. A. Troposcatter B. Ionospheric scatter C. Ducting D. Microwave
Last Answer : B. Ionospheric scatter
Description : Type of transmission path that permits communication in the frequency range from 30 to 60 MHz and over distances form about 1000 to 2000 km. A. Ducting B. Ionospheric scatter C. Microwave D. Troposcatter
Description : An inversion is: a. A decrease of pressure with height b. A decrease of temperature with height c. An increase of temperature with height d. An increase of pressure with height
Last Answer : c. An increase of temperature with height
Description : Helical antennas are oftenused forsatellite trackingatVHFbecauseof a. troposcatter b. superrefraction c. ionospheric refraction d.theFaradayeffect
Last Answer : d.theFaradayeffect
Description : The temperature most suited for con- ducting an industrial process involving a re- versible reactions; most conveniently and profitably is called?
Last Answer : Optimum temperature
Description : Find false statement about effect of sulphur in fuel? (A) It has heating value (B) It helps in electrostatic precipitation of ash in flue gases (C) It leads to corrosion of air heaters, ducting, etc. if flue gas exit temperature is low (D) It erodes furnace walls
Last Answer : (D) It erodes furnace walls
Description : ‘Fanning’ smokestack plumes are observed when A. There is an inversion above the ground surface. B. There is unstable atmosphere. C. There is neutrally stable atmosphere. D. The stack height is below an inversion layer.
Last Answer : A. There is an inversion above the ground surface
Description : Top loading is used in an antenna in order to increase its ______. A. practical height B. beamwidth C. effective height D. input capacitance
Last Answer : C. effective height
Description : Top loading is used in an antenna in order to increase its ___________. A. input capacitance B. beamwidth C. bandwidth D. effective height
Last Answer : D. effective height
Description : Maximum Differential pressure: a. Is the maximum authorized pressure difference between the inside of the fuselage and the atmospheric ambient pressure b. Is the absolute pressure provided by the vacuum ... time limit d. Is the absolute pressure the cabin pressure ducting is designed to carry
Last Answer : a. Is the maximum authorized pressure difference between the inside of the fuselage and the atmospheric ambient pressure
Description : Whenmicrowave signalsfollowthe curvatureofthe earth,thisisknownas a. the Faraday effect b.ducting c. tropospheric scatter d. ionospheric reflection
Last Answer : b.ducting
Description : Maximum Differential pressure: a. Is the maximum authorized pressure difference between the inside of the fuselage and the atmospheric ambient pressure b. Is the absolute pressure provided by the ... time limit d. Is the absolute pressure the cabin pressure ducting is designed to carry
Description : An atomic energy state in which more atoms are in the lower energy state E1 than in the excited state E2, is known as a) population inversion b) normal population c) stimulated population d) atomic population
Last Answer : b) normal population
Description : How to reduce effect of temperature inversion?
Last Answer : Welcome to fluther. This sounds like a homework question and we don’t answer them here but we’ll point you in a direction to look. Are you talking gas, fluid, or solid?
Description : Above the inversion temperature, `mu` (J.T. coefficient)
Last Answer : Above the inversion temperature, `mu` (J.T. coefficient) A. Is positive B. Is zero C. Is negative D. Depends on the gas
Description : Inversion temperature of helium is very low. So when helium is allowed to expand into vacuum it gets
Last Answer : Inversion temperature of helium is very low. So when helium is allowed to expand into vacuum it ... Heated C. Neither cooled, nor heated D. Liquified
Description : Atmospheric temperature increasing at the higher altitudes is called – (1) Radiation (2) Inversion (3) Conduction (4) Convection
Last Answer : (2) Inversion Explanation: The reversal of the normal behaviour of temperature in the troposphere in which a layer of cool air at the surface is overlain by a layer of warmer ... as temperature inversion. Inversions play an important role in determining cloud forms, precipitation, and visibility.
Description : Temperature inversion is
Last Answer : Positive Lapse Rate
Description : ____ is a weather-based indicator for assessing crop development [a] Growing Degree Days [b] Thermal Death Point [c] Sun Clad [d] Heat Units [e] Temperature Inversion
Last Answer : [c] Sun Clad
Description : The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is called __________ temperature. (A) Boyle (B) Inversion (C) Critical (D) Reduced
Last Answer : (A) Boyle
Description : The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is called the __________ temperature. (A) Critical (B) Boyle (C) Inversion (D) Reduced
Last Answer : (B) Boyle
Description : All gases above its inversion temperature, in a throttling process will show (A) A heating effect (B) No change in temperature (C) A cooling effect (D) Either (A) or (C)
Last Answer : (A) A heating effect
Description : Gases are cooled in Joule-Thomson expansion, when it is __________ inversion temperature. (A) Below (B) At (C) Above (D) Either 'b' or 'c'
Last Answer : A) Below
Description : Joule-Thomson co-efficient which is defined as, η = (∂T/∂P)H = 1/Cp (∂H/∂T)P, changes sign at a temperature known as inversion temperature. The value of Joule-Thomson co-efficient at inversion temperature is (A) 0 (B) ∞ (C) +ve (D) -ve
Last Answer : (A) 0
Description : Which one is true for a throttling process? (A) A gas may have more than one inversion temperatures (B) The inversion temperature is different for different gases (C) The inversion ... gases (D) The inversion temperature is the temperature at which Joule-Thomson co-efficient is infinity
Last Answer : (B) The inversion temperature is different for different gases
Description : The temperature at which ferromagnetic material can no longer be magnetised by the outside forces, is termed as the (A) Critical point (B) Curie temperature (C) Inversion temperature (D) Eutectic temperature
Last Answer : (B) Curie temperature
Description : The radiation emitted by a body as a result of its temperature. a. Blackbody Radiation b. Thermal Inversion c. Thermionic Inversion d. Thermal Radiation
Last Answer : Thermal Radiation
Description : How does temperature inversion affect radio transmission?
Last Answer : It can cause vhf and uhf transmission to be propagated far beyond normal line-of-sight distances.
Description : How is the term "temperature inversion" used when referring to radio waves?
Last Answer : It is a condition where layers of warm air are formed above layers of cool air.
Description : Which of the following does NOT form as a result o a low level temperature inversion? w) smog x) sleet y) tornado z) fog
Last Answer : ANSWER: Y -- TORNADO
Description : Atmospheric temperature increasing at the higher altitudes is called (1) Radiation (2) Inversion (3) Conduction (4) Convection
Last Answer : Inversion
Description : Best reason for pressurizing waveguides with dry air A. To maintain propagation B. To maintain temperature of the waveguide C. To reduce the possibility of internal arcing D. To increase the speed of propagation
Last Answer : C. To reduce the possibility of internal arcing
Description : An ungrounded antenna near the ground A. acts as a single antenna of twice the height B. is unlikely to need an earth mat C. acts as antenna array D. must be horizontally polarized
Last Answer : C. acts as antenna array
Description : Factors that determine the radiation resistance of an antenna A. Transmission line length and height of antenna B. The location of the antenna with respect to nearby objects C. It is a constant for all antennas since it is physical D. Sunspot activity and the time of day
Last Answer : B. The location of the antenna with respect to nearby objects
Description : Actual height of antenna should be at least A. one wavelength B. half wavelength C. quarter wavelength D. three-fourth wavelength
Last Answer : C. quarter wavelength
Description : The maximum height of an elliptical orbit is called the A. Perigee B. Apex C. Zenith D. Apogee
Last Answer : D. Apogee
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 : What is the height of a satellite in a synchronous equatorial orbit? A. 42000 mi B. 6800 mi C. 22,300 mi D. 35,860 mi
Last Answer : C. 22,300 mi
Description : As the height of a satellite orbit gets lower, the speed of the satellite _________. A. increases B. decreases C. remains the same D. None of the above
Last Answer : A. increases
Description : What height must a satellite be placed above the surface of the earth in order for its rotation to be equal to earth’s rotation? A. 26,426.4 miles B. 27,426.4 miles C. 23,426.4 miles D. 22,426.4 miles
Last Answer : D. 22,426.4 miles
Description : The speed of the satellite increases as its height in orbit gets A. lower B. higher C. closer to the moon D. closer to the sun
Last Answer : A. lower
Description : For a space wave transmission, the radio horizon distance of a receiving antenna with a height of 64 meters is approximately A. 8 km B. 32 km C. 64 km D. 256 km
Last Answer : B. 32 km
Description : The angle of elevation of the antenna beam is 20°. Calculate the transmission-path distance for an ionospheric transmission that utilizes a layer of virtual height 200 km. Use flat-earth approximation. A. 966 km B. 2100 km C. 1100 km D. 405 km
Last Answer : C. 1100 km