Description : At frequencies above 100 megahertz, the intrinsic (i) region causes a pin diode to act as what?
Last Answer : Variable resistance.
Description : When using frequencies above 30 megahertz, you are normally limited to using what range?
Last Answer : Line of sight.
Description : What type of polarization should be used at medium and low frequencies?
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 range of frequencies are usually referred to as the UHF Band? w) 3 to 30 Megahertz x) 30 to 300 Megahertz y) 300 to 3,000 Megahertz z) 30,000 to 300,000 Megahertz
Last Answer : ANSWER: Y -- 300 TO 3,000 MEGAHERTZ
Description : . If a basic half-wave antenna is mounted vertically, what type of radiation pattern will be produced?
Last Answer : Nondirectional.
Description : In which plane will the half-wave antenna be operating if it is mounted horizontally?
Last Answer : Vertical plane.
Description : It is known that WWV operates on a frequency of 10 megahertz. What is the wavelength of WWV?
Last Answer : 30 meters.
Description : If the fundamental frequency is 200 megahertz, what is the third harmonic?
Last Answer : 600 megahertz.
Description : What type filter is used to block the passage of current for a narrow band of frequencies, while allowing current to flow at all frequencies above or below this band?
Last Answer : . Band-reject.
Description : What type filter is used to allow a narrow band of frequencies to pass through a circuit and attenuate all other frequencies above or below the desired band?
Last Answer : Bandpass.
Description : What is the method of diversity reception where the signal is transmitted on 2 different frequencies over the same path? A. Quadruple B. Frequency C. Polarization D. Space
Last Answer : B. Frequency
Description : What type of disk drive interface has most of the electronics on a controller card mounted in the host computer?
Last Answer : ST-506/412 interface.
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 : _____ 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 : 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 : Which frequency reuse method is less effective because of Faraday’s effect? A. Dual polarization B. Reducing antenna beamwidth C. Zonal rotation D. Spin stabilization
Last Answer : A. Dual polarization
Description : What antenna can be used to minimize the effect of Faraday rotation of polarization? A. Dipole B. Parabolic C. Helical D. Rhombic
Last Answer : C. Helical
Description : The polarization of a radio wave: A. Is perpendicular to the electrostatic field of the antenna B. Is the same direction as the electrostatic field of the antenna. C. Is the same direction ... field of the antenna. D. Is perpendicular to both the electrostatic and magnetic fields of the antenna.
Last Answer : B. Is the same direction as the electrostatic field of the antenna.
Description : What is meant by referring to electromagnetic waves as having circular polarization? A. The electric field is bent into a circular shape. B. The electric field rotates C. The electromagnetic wave continues to circle the earth D. The electromagnetic wave has been generated by a quad antenna
Last Answer : B. The electric field rotates
Description : A helical antenna is used for satellite tracking because of ______. A. Broad bandwidth B. Good front-to-back C. Maneuverability D. Circular polarization
Last Answer : D. Circular polarization
Description : The polarization of a discone antenna is _____. A. Horizontal B. Vertical C. Omni D. Directional
Last Answer : B. Vertical
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 : The magnetic field of an antenna is perpendicular to the earth. The antenna’s polarization ___
Last Answer : is horizontal
Description : Describe with respect to antenna (i) radiation pattern (ii) directive gain (iii) power gam (iv) polarization
Last Answer : (i) Radiation pattern:-A graph or diagram which tells us about the manner in which an antenna radiates more power in different directions is known as the radiation patteren of antenna. ( ... as the direction of the electric vector in the electromagnetic wave radiated by the transmitting antenna.
Description : Define the following terms: (i) Polarization (ii) Antenna gain (iii)Antenna resistance (iv)Directivity
Last Answer : i) Polarization:- It is defined as the direction of electric field vector in the EM wave radiated by the transmitting antenna. ii) Antenna Gain:- Antenna gain is defined as the ratio of ... in only one direction in which the radiation is maximum. That is directivity = Max. directive gain
Description : A universally mounted gyro has how many degrees of freedom?
Last Answer : Two.
Description : A universally mounted gyro has how many gimbals?
Description : Rotating the plane of polarization of a wavefront by passing it through a ferrite device is called what?
Last Answer : . Faraday rotation.
Description : What is the polarization of the energy radiated by a vertical slot?
Last Answer : Horizontal.
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 : 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 : The direction of what field is used to designate the polarization of a wave?
Last Answer : Electric (E) field.
Description : What is the WAVELENGTH of the carrier wave, in meters, of a radio station which is broadcasting at a frequency of 100 megahertz?
Last Answer : ANSWER: 3 METERS
Description : A disadvantage of using a trap antenna. A. It will radiate harmonics B. It can only be used for single-bad operation C. It is too sharply directional at lower frequencies D. It must be neutralized
Last Answer : A. It will radiate harmonics
Description : ECE Board Exam March 1996 An antenna which is not resonant at a particular frequencies and so can be used over a wide band of frequencies and so can be used over a wide band of frequencies is called A. aperiodic B. boresight C. cassegrain D. top-loaded
Last Answer : A. aperiodic
Description : Hertz antenna are predominantly used with frequencies above
Last Answer : 2MHz
Description : What type of insulator works well at very high frequencies?
Last Answer : A shorted quarter-wave section called a metallic insulator.
Description : What type of coupling is most effective at high frequencies?
Last Answer : Impedance coupling.
Description : Horizontally mounted moving iron instruments use (a) Eddy current damping (b) Electromagnetic damping (c) Fluid friction damping (d) Air friction damping
Last Answer : Horizontally mounted moving iron instruments use Air friction damping
Description : Non-passing sight distance along a road is the longest distance at which the driver of a moving vehicle, may see an obstacle on the pavement (A) 10 cm high (B) 25 cm high (C) 50 cm high (D) 100 cm high
Last Answer : Answer: Option A
Description : Over taking time required for a vehicle with design speed 50 km ph and overtaking acceleration 1.25 m/sec2 to overtake a vehicle moving at a speed 30 km ph, is (A) 5.0 secs (B) 6.12 secs (C) 225.48 secs (D) 30 secs
Last Answer : Answer: Option B
Description : At very high frequencies, what characteristics are displayed by ordinary insulators?
Last Answer : The characteristics of the dielectric of a capacitor.
Description : . Why are coaxial lines more efficient at microwave frequencies than two-wire transmission lines?
Last Answer : The electromagnetic fields are completely confined
Description : A cavity that vibrates at its natural frequency produces a louder sound than at other frequencies. What term is used to describe this phenomenon?
Last Answer : Resonance.
Description : What term is used to describe the frequency at which the filter circuit changes from the point of rejecting the unwanted frequencies to the point of passing the desired frequencies?
Last Answer : Frequency cutoff (fco).