Description : What makes an antenna physically long but electrically short? A. Top loading B. Adding C in series C. Adding L in series D. All of these
Last Answer : B. Adding C in series
Description : What is the effect of adding a capacitor in series with an antenna? A. The antenna’s resonant frequency will increase B. The antenna’s resonant frequency will decrease C. The antenna will be physically 5% longer than its electrical length D. A capacitor is never added in series with an antenna
Last Answer : A. The antenna’s resonant frequency will increase
Description : Known as the technique for adding a series inductor at or near the center of an antenna element in order to cancel the capacitive reactance of an antenna. A. Dipole B. Center loading C. Reflector D. loading coil
Last Answer : D. loading coil
Description : If an antenna is too short for the wavelength being used, the effective length can be increased by adding: A. capacitance in series B. inductance in series C. resistance in parallel D. resistance in series
Last Answer : B. inductance in series
Description : To electrically decrease the length of an antenna. A. add an inductor in series B. add an inductor in parallel C. add a resistor in series D. add a capacitor in series
Last Answer : D. add a capacitor in series
Description : The advantage of using top loading in a shortened HF vertical antenna is A. lower quality factor B. greater structural strength C. higher losses D. improved radiation efficiency
Last Answer : D. improved radiation efficiency
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 : When speaking of antennas. ______ is a section which would be a complete antenna by itself. A. image B. top loading C. bay D. quarterwave
Last Answer : C. bay
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 : Increasing the resonant frequency of an end-fed Marconi antenna can be done by A. adding a capacitor in series and reducing the physical length B. adding an inductor in series C. adding an inductor in series D. All of these
Last Answer : A. adding a capacitor in series and reducing the physical length
Description : To lengthen an antenna electrically, add a A. resistor B. battery C. condult D. coil
Last Answer : D. coil
Description : For a shortened vertical antenna, where should a loading coil be placed to minimize losses and produce the most effective performance? A. As low as possible on the vertical radiator B. Near the center of the vertical radiator C. As close to the transmitter as possible D. At a voltage node
Last Answer : B. Near the center of the vertical radiator
Description : What happens to the bandwidth of an antenna as it is shortened through the use of loading coils? A. It is increased B. It is decreased C. No change occurs D. It becomes flat
Last Answer : A. It is increased
Description : What is the estimated medium wind loading in the Philippines for antenna tower design? A. 300 kph B. 100 kph C. 200 kph D. 250 kph
Last Answer : C. 200 kph
Description : What is the estimated medium wind loading in the Philippines for antenna tower design? A. 200 kph B. 250 kph C. 300 kph D. 100 kph
Last Answer : A. 200 kph
Description : The effect of adding parasitic elements of a Hertz dipole is to A. make the antenna more omnidirectional B. reduce its resonant frequency C. increase the antenna’s power gain D. All of these
Last Answer : C. increase the antenna’s power gain
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 would be the physical length of a tpical coaxial transmission line that is electrically one-quarter wavelength long at 14.1 MHz? A. 20 meters B. 3.51 meters C. 2.33 meters D. 0.25 meter
Last Answer : B. 3.51 meters
Description : When a capacitor is connected in series with a Marconi antenna? A. Antenna open circuit stops transmission B. An inductor of equal value must be added C. No change occurs to antenna D. Antenna resonant frequency increases
Last Answer : D. Antenna resonant frequency increases
Description : Increasing the electrical length of an antenna means A. add an inductor in parallel B. add a capacitor in series C. add an inductor series D. add a resistor is series
Last Answer : C. add an inductor series
Description : How is it possible to lower the resonant frequency of Hertz dipole antenna? A. By reducing the frequency at the transmitter B. By connecting a capacitor in series with the antenna C. By the connecting a resistor in series with the antenna D. By connecting an inductor in series with the antenna
Last Answer : D. By connecting an inductor in series with the antenna
Description : The current maximum in a Marconi antenna is found at A. the base of the antenna B. the center of the antenna C. some point between the base and the center of the antenna D. the top of the antenna
Last Answer : A. the base of the antenna
Description : What is the meaning of forward power? A. The power traveling from the transmitter to the antenna. B. The power radiated from the top of an antenna system. C. The power produced during the positive half of an RF cycle. D. The power used to drive a linear amplifier.
Last Answer : A. The power traveling from the transmitter to the antenna.
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 : Shortening effect of an antenna that makes it appear as if it were 5% longer. A. End effect B. Flywheel effect C. Skin effect D. Capture effect
Last Answer : A. End effect
Description : A dipole antenna requires to be fed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11kW ... Gain referred to this particular dipole). A. 4.75 B. 2.6 C. 1.81 D. 4.24
Last Answer : B. 2.6
Description : A dipole antenna requires to be feed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11 ... ( Gain referred to this particular dipole) A. 4.24 B. 1.81 C. 4.75 D. 2.6
Last Answer : D. 2.6
Description : “Booting the System” means (1) loading the operating system (2) dismissing the computer (3) running an application program called “Booting”. (4) physically kicking the computer
Last Answer : loading the operating system
Description : The concept of an electrically short, medium and long line is primarily based on the A) Nominal voltage of the line B) Physical length of the line C) Wave length of the line D) Power transmitted over the line
Last Answer : The concept of an electrically short, medium and long line is primarily based on the Physical length of the line
Description : Define loading?
Last Answer : A large value of Rc cannot be used in a circuit since,a large value of resistance requires a large chip area.For large Rc, quiescent drop across it increases and hence a large power supply is required ... source can also be used as an active load for an amplifier to obtain a very large voltage gain.
Description : _____ is an antenna made up of a number of full wavelengths A. Elementary doublet B. Log-periodic C. Long wire D. Whip
Last Answer : C. Long wire
Description : Which of the following antennas receive signals in the horizontal plane equality well from all directions? A. Horizontal Hertz antenna B. Vertical loop antenna C. Vertical Yagi antenna D. A vertical antenna which is a quarter-wavelength long
Last Answer : D. A vertical antenna which is a quarter-wavelength long
Description : An antenna which is one-tenth wavelength long A. Hertzian dipole B. Loop antenna C. Marconi antenna D. Elementary doublet
Last Answer : D. Elementary doublet
Description : Type of emission produced by one of the early radio transmitter in trains of damped RF ac waves where its oscillator is coupled to a long wire antenna, normally used in radio telegraph and having sidebands on its carrier. A. Digital emission B. Key emission C. Cycle emission D. Spark emission
Last Answer : D. Spark emission
Description : It is an average power of a radio transmitter supplied to the antenna transmission line taken during a long sufficient interval of time and compared with the lowest frequency encountered in the modulation ... operating conditions. A. Carrier power B. Rated power C. Mean power D. Peak envelop power
Last Answer : C. Mean power
Description : Stacking elements in a transmitting antenna system A. increases the field strength at the receiving antenna B. increases the directivity of the transmitter antenna C. decrease the size of the lobe in the radiation pattern D. both A and B
Last Answer : D. both A and B
Description : The parasitic element of an antenna system will A. decrease its directivity B. increase its directivity C. give the antenna unidirectional properties D. both B and C
Last Answer : D. both B and C
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 : Referred to as a ferrite device that can be used in lieu of a duplexer to isolate a microwave transmitter and receiver when both are connected to the same antenna. A. Isolator B. Circulator C. Coupler D. Diode.
Last Answer : B. Circulator
Description : Which of the following concepts means adding new concepts to a program as it runs? (A) Data hiding (B) Dynamic loading (C) Dynamic typing (D) Dynamic binding
Last Answer : (B) Dynamic loading
Description : How is a wattmeter electrically connected in a circuit? A. In series B. In parallel C. In series-parallel D. Inductively
Last Answer : Answer: C
Description : Pick out the wrong statement. (A) α-particle emission from a radioactive element makes it electrically negative (B) β-particle emission from a radioactive element makes it electrically ... ) The disintegration constant of a radioactive isotope is independent of pressure, temperature or concentration
Last Answer : (C) A radioactive element having a half life period of 20 years will completely disintegrated in 40 years
Description : Which antenna does not use the ground? A. Marconi B. Yagi C. Hertz D. Rhombic
Last Answer : B. Yagi
Description : Which antenna is not grounded at one end? A. Hertz B. Marconi C. Dipole D. Whip
Last Answer : C. Dipole
Description : Which one is an antenna coupling unit? A. Coupler B. Diplexer C. Lecher wire D. Duplexer
Last Answer : B. Diplexer
Description : One of the following is not a reason for the use of an earth mat A. impossibility of a good ground connection B. provision of an earth for the antenna C. protection of personnel working underneath D. improvement of the radiation pattern of the antenna
Last Answer : C. protection of personnel working underneath
Description : Which antenna is not a wideband? A. Discone B. Folded dipole C. Helical D. Marconi
Last Answer : D. Marconi
Description : Not a reason for the use of an antenna coupler. A. To make the antenna look resistive B. To provide the output amplifier with the correct load impedance C. To discriminate against harmonics D. To prevent re-radiation of the local oscillator
Last Answer : D. To prevent re-radiation of the local oscillator
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 : One of the following is very useful as a multiband HF receiving antenna. A. Parabolic antenna B. Elementary doublet C. Log-periodic D. Square loop
Last Answer : C. Log-periodic