Description : Transmission lines when connected to antenna have A. capacitive load B. resistive load whose resistance is less than characteristics impedance C. resistive load at the resonant frequency D. resistive load whose resistance is greater than the characteristic impedance of the line
Last Answer : C. resistive load at the resonant frequency
Description : What do you call the phenomenon in digital circuits that describe the duration of time a digital signal passes a circuit? A. Transmission time B. Elapsed time C. Propagation delay D. Travel delay
Last Answer : C. Propagation delay
Description : What is transit time (time delay) of a 50-ft length transmission line of the above problem? A. 50 ns B. 100 ns C. 75 ns D. 65 ns
Last Answer : C. 75 ns
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 : Strategic planning: (a) Addresses the organization's basic mission or business, issuing broad statements of purpose or direction that have a long lead time. (b) Involves managers in each unit of ... overall plans of the organization. (d) Determines the day-to-day operations within an organization.
Last Answer : (a) Addresses the organization's basic mission or business, issuing broad statements of purpose or direction that have a long lead time.
Description : . A non-resonant line is a line that has no standing waves of current and voltage on it and is considered to be flat. Why is this true?
Last Answer : The load impedance of such a line is equal to Z0.
Description : The total propagation delay time from transmission to reception of signals from a ground transmitter to ground receiver with angle of elevation at 10 degrees respectively is A. 273 ms B. 239 ms C. 275 ms D. 260 ms
Last Answer : A. 273 ms
Description : What is the delay time for satellite transmission from earth transmitter to earth receiver? A. 0.5 s B. 1.0 s C. 5 ms D. 0.25 ms
Last Answer : A. 0.5 s
Description : Which antenna is not properly terminated? A. Resonant B. Non-resonant C. Isotropic D. Whip
Last Answer : A. Resonant
Description : Which is a non-resonant antenna? A. Rhombic antenna B. Folded dipole C. End-fire array D. Yagi-Uda antenna
Last Answer : A. Rhombic antenna
Description : Antenna which is not properly terminated A. Isotropic B. Non-resonant C. Whip D. Resonant
Last Answer : D. Resonant
Description : Which is the non-resonant antenna? A. Broadside Antenna B. Folded Dipole C. Rhombic antenna D. End fire array
Last Answer : C. Rhombic antenna
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
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 : 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 : 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 : If the length of an antenna is changed from 2.5 meters to 2.8 meters, its resonant frequency will A. increase B. depend on the velocity factor so the resonant frequency can either be increased or decreased C. will be unchanged D. decrease
Last Answer : D. decrease
Description : If the length of a Hertz dipole is decreased A. its resonant frequency will be lowered its distributed inductance will be increased B. its distributed inductance will be decreased C. its ... frequency will be increased D. its distributed capacitance between the antenna and ground will be increased.
Last Answer : C. its resonant frequency will be increased
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 : Determine the lower half-power frequency of a class-C amplifier having upper half-power frequency of 10.025 MHz, a resonant frequency 5 MHz and a circuit Q of 10. A. 1.0025 MHz B. 10.525 MHz C. 0.5 MHz D. 10 MHz
Last Answer : A. 1.0025 MHz
Description : Where do the maximum current and minimum voltage values on a resonant Hertz dipole exist? A. Center of the antenna B. Near the end of the antenna C. Near the center of the antenna D. Ends of the antenna
Last Answer : A. Center of the antenna
Description : Highest theoretical frequency that can be processed at a sampling rate without aliasing. A. Folding frequency B. Resonant frequency C. Natural frequency D. Critical frequency
Last Answer : A. Folding frequency
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 : In telecommunications when we call data communications it means the transmission of________. A. Voice and video B. Voice C. Video D. Computer data
Last Answer : D. Computer data
Description : ________ dispersion is caused by the difference in the propagation times of light rays that take different paths down a fiber. a. Material dispersion b. Wavelength dispersion c. Modal dispersion d. Delay dispersion
Last Answer : c. Modal dispersion
Description : What is the propagation delay when a signal is transmitter by an earth station to a geosynchronous satellite about 38,500 km above earth’s equator and then received by the same earth station? A. 256 msec B. 128 msec C. 300 msec D. 400 msec
Last Answer : A. 256 msec
Description : The round-trip propagation delay between two earth stations through a geosynchronous satellite is A. 500 to 600 ms B. 300 to 400 ms C. 600 to 700 ms D. 400 to 500 ms
Last Answer : A. 500 to 600 ms
Description : The maximum propagation delay of a geostationary satellite is A. 278 ms B. 239 ms C. 300 ms D. 250 ms
Last Answer : A. 278 ms
Description : What is the delay time for satellite transmissions from earth transmitter to earth receiver? A. 0.5 s B. 1s C. 5 ms D. 0.25 s
Description : What is the minimum propagation delay of a geostationary satellite? A. 278 ms B. 239 ms C. 300 ms D. 600 ms
Last Answer : B. 239 ms
Description : What is the time delay introduced by a 75-ft coaxial cable with a dielectric constant of 2.3? A. 1.54 ns B. 11.5 ns C. 115.6 ns D. 1156 ns
Last Answer : C. 115.6 ns
Description : RADAR means A. Radio detection and rating B. Radio detection and ranging C. Radio distance and ranging D. Radio delay and ranging
Last Answer : B. Radio detection and ranging
Description : What is the phase delay of an 800 Hz voice signal if the phase shift is 15 degrees? A. 1.25 µsec B. 52 µsec C. 83.33 µsec D. 26 µsec
Last Answer : B. 52 µsec
Description : How would one squeeze more channels of communication into TDM frames of standard length? A. Shorten the time delay for each channel B. Raise the amplitude C. Add modulators D. Remove the synchronizing pulses
Last Answer : A. Shorten the time delay for each channel
Description : A law that specifically requires the service of a duly registered electronics and communications engineer in the designing installation and construction, operation and maintenance of radio stations. A. Act 3846 B. LOl 1000 C. R.A. 5734 D. Dept. order 88
Last Answer : D. Dept. order 88
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 : It is useful to refer to an isotropic radiator. A. when comparing the gains of directional antennas B. when testing a transmission line for standing wave ratio C. when (in the northern hemisphere) directing the transmission D. when using a dummy load to tune a transmitter
Last Answer : A. when comparing the gains of directional antennas
Description : What is driven element? A. Always the rearmost element B. Always the forward most element C. The element fed by the transmission line D. The element connected to the rotator
Last Answer : C. The element fed by the transmission line
Description : A component that samples the microwave signal travelling in one direction down to the transmission line A. Isolator B. Combiner C. Directional coupler D. Attenuator
Last Answer : C. Directional coupler
Description : What distortion is not caused by transmission line characteristics? A. Phase distortion B. Pulse shape distortion C. Spacing bias distortion D. Amplitude distortion
Last Answer : C. Spacing bias distortion
Description : What type of balun (balanced-to-unbalanced) is used in high frequency applications? A. Transformer type balun B. A specially configured coaxial transmission line C. A specially configured parallel-wire line D. A λ/2 transformer balun
Last Answer : B. A specially configured coaxial transmission line
Description : In transmission line, which of the following is the first step in the procedure of using stub matching? A. Calculate stub susceptance. B. Calculate load admittance C. Connect stub to load D. Transform conductance to resistance
Last Answer : B. Calculate load admittance
Description : The presence of standing waves on a transmission line is the result of A. a high level of attenuation on the line. B. terminating the line by a resistive load equal in value to the surge impedance ... input power to below its critical level. D. an impedance mismatch between the load and the line.
Last Answer : D. an impedance mismatch between the load and the line.
Description : Which of the following characterizes a properly terminated transmission line? A. The line loss is minimum. B. The standing wave ratio is minimum. C. The input impedance is twice the load impedance. D. The standing wave ratio is one.
Last Answer : D. The standing wave ratio is one.
Description : What is the input impedance of a transmission line if its characteristic impedance is 300 Ω and the load is 600 Ω? Assume a quarter wavelength section only. A. 150 kΩ B. 150 mΩ C. 150 Ω D. 2 Ω
Last Answer : C. 150 Ω
Description : What is the phase coefficient in radians per unit length of a transmission line at the frequency of 10 MHz if the velocity of propagation is 2.5x108 m/s? A. 0.25 B. 2.5 C. 0.35 D. 3.5
Last Answer : A. 0.25
Description : What is the propagation velocity of a signal in a transmission line whose inductance and capacitance are 5μH/m and 20μF/m respectively? A. 100x103 m/s B. 100 m/s C. 10x103 m/s D. 100x106 m/s
Last Answer : A. 100x103 m/s
Description : Which of the following is considered the most frequently used transmission line? A. Two-wire open line B. Twin lead C. Rigid coaxial line D. Flexible coaxial line
Last Answer : D. Flexible coaxial line
Description : When is it useful to refer to an isotropic radiator? A. When comparing the gains of directional antennas B. When testing a transmission line for standing wave ratio C. When (in the northern ... ) directing the transmission in a southerly direction D. When using a dummy load to tune a transmitter
Last Answer : A. When comparing the gains of directional antennas
Description : A coaxial cable has 7dB of reflected power when the input is 5 watts. What is the output of the transmission line? A. 5 watts B. 2.5 watts C. 1.25 watts D. 1 watt
Last Answer : D. 1 watt