Description : _____ of an antenna is a measure of how the antenna concentrates its radiated power in a given direction. A. Efficiency B. Power C. Gain D. Polarization
Last Answer : C. Gain
Description : What determines antenna polarization? A. The frequency of the radiated wave B. The direction of the radiated wave C. The direction of the magnetic field vector D. The direction of the electric field vector
Last Answer : D. The direction of the electric field vector
Description : It is a measure of the microwave power radiated from an antenna as a function of angular direction from the antenna axis. A. Antenna pattern B. Polarization C. Beamwidth D. Sidelobes
Last Answer : C. Beamwidth
Description : What characteristic(s) of radiated energy is (are) altered to achieve electronic scanning?
Last Answer : Frequency or phase.
Description : If a wave's electric lines of force rotate through 360 degrees with every cycle of rf energy, what is the polarization of this wave?
Last Answer : Circular polarization.
Description : When a wavefront is radiated into a waveguide, what happens to the portions of the wavefront that do not satisfy the boundary conditions?
Last Answer : Decrease to zero.
Description : What are three ways of controlling radiated emi during transmission?
Last Answer : a) physical separation of the antenna (b) limiting bandwidth of the antenna (c) use of directional antennas
Description : If a target is on the bearing axis of the radiated beam, what is the input to the bearing IF channel?
Last Answer : Zero.
Description : What width is the pulse radiated by fire-control tracking radar?
Last Answer : Very narrow.
Description : How many major lobes are radiated by a parabolic reflector?
Last Answer : One
Description : What is the term that is used to describe narrowness in the radiated beam of an antenna?
Last Answer : Antenna directivity.
Description : Capacitive tuning by inserting a ring into the cavity slot of a magnetron is accomplished by what type of tuning mechanism?
Last Answer : . A cookie-cutter tuner
Description : Magnetron tuning by altering the surface-to-volume ratio of the hole portion of a hole-and-slot cavity is what type of tuning?
Last Answer : Inductive.
Description : Without strapping, the resonant cavities of a hole-and-slot anode are connected in what manner?
Last Answer : Series.
Description : ______ polarization is employed in FM broadcasting A. Horizontal B. Vertical C. Circular D. Bidirectional
Last Answer : A. Horizontal
Description : _____ polarization is employed in AM broadcasting A. Horizontal B. Vertical C. Circular D. Omnidirectional
Last Answer : B. Vertical
Description : In horizontal-dipole antenna, the polarization is A. in the vertical direction B. in the horizontal direction C. circular D. measured at the center of the antenna
Last Answer : B. in the horizontal direction
Description : Which antenna radiates an omnidirectional pattern in the horizontal plane with vertical polarization? A. Marconi antenna B. Discone antenna C. Horn antenna D. Helical antenna
Last Answer : A. Marconi antenna
Description : Which does not use vertical polarization antenna? A. AM Broadcasting B. FM Broadcasting C. Mobile Communications D. Satellite Communications
Last Answer : B. FM Broadcasting
Description : What is the polarization of a discone antenna? A. Vertical B. Horizontal C. Circular D. Spiral
Last Answer : A. Vertical
Description : Most AM broadcasts employ ___ polarization while most FM broadcasts employ ___ polarization of the radio wave. A. vertical, vertical B. vertical, horizontal C. horizontal, vertical D. horizontal, horizontal
Last Answer : B. vertical, horizontal
Description : The electric field lies in a plane parallel to the earth’s surface. A. Elliptical polarization B. Horizontal polarization C. Vertical polarization D. Circular polarization
Last Answer : B. Horizontal polarization
Description : The electric field lines in a plane perpendicular to the earth’s surface. A. Elliptical polarization B. Circular polarization C. Horizontal polarization D. Vertical polarization
Last Answer : D. Vertical polarization
Description : The polarization of a discone antenna is _____. A. Horizontal B. Vertical C. Omni D. Directional
Description : Pick up the correct statement from the following: (A) When the electric field oscillates in the direction of the electric vector, a plane polarised wave is formed (B) When the electric vector is ... right angles to the plane of incidence, horizontal polarization wave is formed (D) All of these
Last Answer : Answer: Option D
Description : .In electromagneticwaves,polarization a. is caused by reflection b.isdue to the transversenature ofthewaves c. results from the longitudinal nature of the waves d. is always vertical in an isotropic medium
Last Answer : b.isdue to the transversenature ofthewaves
Description : There are three commonly detectable points of zero polarization of diffuse sky radiation, neutral points, lying along the vertical circle through the sun. Which of the following is NOT one of these points? Is it the: w) Arago Point x) Babinet Point y) Brewster Point z) Longfellow Point
Last Answer : ANSWER: Z -- LONGFELLOW POINT
Description : Rotating the plane of polarization of a wavefront by passing it through a ferrite device is called what?
Last Answer : . Faraday rotation.
Description : Describe three ways to prevent polarization.
Last Answer : Vent the cell, add a material rich in oxygen, and use a material that will absorb hydrogen.
Description : Describe three ways to prevent polarization
Last Answer : vent the cell, add a material rich in oxygen, and use a material that will absorb hydrogen.
Description : What type of polarization should be used if an antenna is mounted on a moving vehicle at frequencies below 50 megahertz?
Last Answer : Vertical polarization.
Description : What is an advantage of using horizontal polarization at high frequencies?
Last Answer : Less interference is experienced by man-made noise sources
Description : What type of polarization should be used at medium and low frequencies?
Description : The direction of what field is used to designate the polarization of a wave?
Last Answer : Electric (E) field.
Description : Is solar energy radiated?
Last Answer : Yes, among other ways, solar energy is radiated. That is whatheats up the Earth and the other planets, mostly.
Description : Which of the following reaction is the main cause of energy radiated from Sun? (1) Nuclear fission (2) Nuclear fusion (3) Chemical reaction (4) Diffusion reaction
Last Answer : (2) Nuclear fusion Explanation: The Sun is a main-sequence star, and thus generates its energy bynuclear fusion of hydrogen nuclei into helium. In its core, the Sunfuses 620 million metric tons of hydrogen each second.
Description : How will you increase the gain of an antenna? A. By adding several antennas in parallel B. By focusing the radiated energy in one desired direction C. By making antenna rods thicker D. By making the antenna size larger
Last Answer : B. By focusing the radiated energy in one desired direction
Description : What do you call the energy that was not radiated into space or completely transmitted? A. Incident waves B. Captured waves C. Standing waves D. Modulated waves
Last Answer : C. Standing waves
Description : Energy that has neither been radiated into space nor completely transmitted. A. Captured waves B. Incident waves C. Standing waves D. Modulated waves
Description : The energy radiated from a surface Q at absolute temperature T is related as (A) Q ∝ T 2 (B) Q ∝ T 4 (C) Q ∝ T 3 (D) None of these
Last Answer : (B) Q ∝ T
Description : The atmosphere near the earth's surface is heated from below. Which of the following does not significantly contribute to this heating -----------? A. Conduction of heat upward from a ... infrared energy that has been radiated from the surface D. Heat energy from the earth's interior (Answer)
Last Answer : D. Heat energy from the earth’s interior (Answer)
Description : It is the ratio of the radiated to the reflected energy:
Last Answer : Radiation efficiency
Description : What process produces most of the energy that is radiated by the Sun? w) gravitational contraction x) chemical combustion y) nuclear fusion z) nuclear fission
Last Answer : ANSWER: Y -- NUCLEAR FUSION
Description : To develop the correct mathematical description of the distribution of radiated energy of a blackbody with respect to wavelength for a given temperature, Planck found it necessary to assume that the molecular ... units or quanta y) radiant energy in a continuous form z) none of the above.
Last Answer : ANSWER: X -- RADIANT ENERGY IN DISCRETE UNITS OR QUANTA
Description : The potential difference across a 4 ohm resistor is 20 volts. Assuming that all of the energy dissipated by this resistor is in the form of heat, how many joules of heat are radiated in 10 seconds?
Last Answer : ANSWER: 1000 JOULES
Description : The energy radiated by Sun on a bright Sunny day is approximately: (A) 700 W/m² (B) 800 W / m² (C) 1 kW / m² (D) 2 kW / m²
Last Answer : The energy radiated by Sun on a bright Sunny day is approximately: 1 kW / m²
Description : What percent of the input energy is radiated by filament lamps ? (1) 2 to 5 percent (2) 10 to 15 percent (3) 25 to 30 percent (4) 40 to 50 percent
Last Answer : less than 10 percentage
Description : The energy in a magnetic material is due to which process? a) Emf b) Magnetization c) Magnetostriction d) Polarization
Last Answer : b) Magnetization
Description : When microwave energy is passed through a piece of ferrite in a magnetic field, another effect occurs. If the frequency of the microwave energy is much greater than the electron wobble frequency, the plane of polarization of the wavefront is rotated. This is known as
Last Answer : Faraday Rotation Effect
Description : The vertical-deflection plates are used to reproduce what function?
Last Answer : Amplitude.