Description : What is the typical velocity factor of coaxial cables? A. 0.6 to 0.8 B. 0.3 to 0.5 C. 0.5 to 0.9 D. 0.4 to 0.6
Last Answer : A. 0.6 to 0.8
Description : What is the typical velocity factor of open-wire line? A. 0.9 B. 0.8 C. 0.5 D. 0.7
Last Answer : A. 0.9
Description : A pair of current-carrying conductors is not considered a transmission line unless it is at least ___ λ long at the signal frequency. A. 0.1 B. 0.3 C. 0.2 D. 0.4
Last Answer : A. 0.1
Description : The velocity of a wave travelling in the air medium without transmission lines or waveguides(wireless) is a) 6 x 10 8 b) 3 x 10 8 c) 1.5 x 10 8 d) 9 x 10 8
Last Answer : b) 3 x 10 8
Description : What is the meaning of the term velocity factor of a transmission line? A. The ratio of the characteristic impedance of the line to the terminating impedance B. The index of shielding for coaxial ... The velocity of the wave on the transmission line divided by the velocity of light in a vacuum.
Last Answer : D. The velocity of the wave on the transmission line divided by the velocity of light in a vacuum.
Description : What determines the velocity factor in a transmission line? A. The termination impedance B. The line length C. Dielectrics in the line D. The center conductor resistivity
Last Answer : C. Dielectrics in the line
Description : What is the meaning of the term velocity factor of a transmission line? A. The index of shielding for coaxial cable B. The velocity of the wave on the transmission line multiplied by the velocity of ... The velocity of the wave on the transmission line divided by the velocity of light in a vacuum
Last Answer : D. The velocity of the wave on the transmission line divided by the velocity of light in a vacuum
Description : What determines the velocity factor in transmission line? A. The center conductor resistivity B. Dielectrics in the line C. The termination impedance D. The line length
Last Answer : B. Dielectrics in the line
Description : Referred to the dielectric constant of a transmission line material. A. Inductance and capacitance B. Velocity factor C. Characteristic impedance D. Propagation velocity
Last Answer : B. Velocity factor
Description : ECE Board Exam March 1996 What is the transmission rate of a system for transmitting the output of a microcomputer to a line printer operating at a speed of 30 lines/minute? Assume that the line printer has 8 bits ... and prints out 80 characters/line. A. 800 bps B. 400 bps C. 320 bps D. 640 bps
Last Answer : C. 320 bps
Description : What is the actual length in feet of a one-quarter wavelength of a coax with a velocity factor of 0.68 to 30 MHz? A. 19.26 B. 5.6 C. 17.82 D. 16.97
Last Answer : B. 5.6
Description : What is the velocity factor for non-foam dielectric 50 or 75 ohm flexible coaxial cable such as RG 8, 11, 58 and 59? A. 2.70 B. 0.66 C. 0.30 D. 0.10
Last Answer : B. 0.66
Description : What line has a typical velocity factor of about 0.8? A. Shielded pair B. Flexible coaxial C. Twin-lead D. Open-wire line
Last Answer : C. Twin-lead
Description : What is the velocity factor for non-foam dielectric 50 or 75 ohm flexible coaxial cable such as RG 8, 11, 58 and 59? A. 2.70 B. 0.10 C. 0.66 D. 0.30
Last Answer : C. 0.66
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 : 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 : For steady ideal fluid flow, the Bernoulli's equation states that the (A) Velocity is constant along a stream line (B) Energy is constant throughout the fluid (C) Energy is constant along a stream line, but may vary across stream lines (D) None of these
Last Answer : (C) Energy is constant along a stream line, but may vary across stream lines
Description : Man-made noise is usually from _______. A. transmission over power lines and by ground wave B. sky-wave C. space-wave D. troposphere
Last Answer : A. transmission over power lines and by ground wave
Description : Transmission of printed material over telephone lines. A. Video text B. Facsimile C. Encoding D. Xerox copy
Last Answer : B. Facsimile
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 : Transmission lines are either balanced or unbalanced with respect to _________. A. negative terminal B. input C. ground D. positive terminal
Last Answer : C. ground
Description : What is meant by antenna gain? A. The final amplifier gain minus the transmission line losses (including any phasing lines present) B. The ratio of the amount of power produced by the antenna ... D. The numeric ratio relating the radiated signal strength of an antenna to that of another antenna
Last Answer : D. The numeric ratio relating the radiated signal strength of an antenna to that of another antenna
Description : What is actual length in feet of a one-half wavelength of a coax with a velocity factor of 0.59 at 26 MHz? A. 11.16 B. 40.29 C. 42.46 D. 46.28
Last Answer : A. 11.16
Description : What is the actual length in feet of a one-half wavelength of a coax with a velocity factor of 0.63 at 28 MHz? A. 44.28 B. 43.46 C. 11.07 D. 46.27
Last Answer : C. 11.07
Description : What is the actual length in feet of a one-quarter wavelength of a coax with a velocity factor of 0.695 at 45 MHz? A. 17.82 B. 19.26 C. 16.28 D. 16.97
Last Answer : C. 16.28
Description : What is the velocity factor of coaxial cable with a characteristic impedance of 50Ω and capacitance of 30pF/ft and inductance of 75 nH/ft? A. 0.58 B.0.68 C. 0.98 D. 0.81
Last Answer : B.0.68
Description : What is the characteristic impedance of a single wire with a diameter d= 0.25 mm placed at the center between grounded parallel planes separated by 1 mm apart. The wire is held by a material with a velocity factor of 0.75. A. 85 Ω B. 63 Ω C. 50 Ω D. 75 Ω
Last Answer : D. 75 Ω
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 : A three-phase alternator is operating at 450 volts with the switchboard ammeter indicating 300 amps. The kw meter currently indicates 163.6 KW, with a power factor of 0.7. If the power factor increases to 0.8, the KW meter reading would increase by ___ A. 17.8 KW B. 23.2 KW C. 30.6 KW D. 37.8 KW
Last Answer : Answer: B
Description : How does the electric field strength of a standard broadcast station vary with the distance from the antenna? A. The field strength of a standard broadcast station vary with the distance from ... the distance from the antenna D. The field strength varies inversely as the distance from the antenna
Last Answer : D. The field strength varies inversely as the distance from the antenna
Description : What causes the maximum usable frequency to vary? A. The temperature of the ionosphere B. The speed of the winds in the upper atmosphere C. The type of weather just below the ionosphere D. The amount of radiation received from the sun
Last Answer : D. The amount of radiation received from the sun
Description : _______ is more prevalent in analog signals that have steep slopes or whose amplitudes vary rapidly. A. Peak limiting B. Quantization noise C. Granular noise D. Slope overload
Last Answer : D. Slope overload
Description : ECE Board Exam March 1996 One type of pulse communications system uses pulse that appear as a group, and which vary in number according to the loudness of the voice. This type of ... A. pulse duration modulation B. pulse amplitude modulation C. pulse code modulation D. pulse position modulation
Last Answer : A. pulse duration modulation
Description : Determine the dB gain of a receiving antenna which delivers a microvolt signal to a transmission line over that of an antenna that delivers a 20 microvolt signal under identical circumstances. A. 10 dB B. 6 dB C. 3 dB D. 8 dB
Last Answer : B. 6 dB
Description : What is the optimum reverberation time at 500 to 1000 Hz of an auditorium? A. 0.9 to 1.1 s B. 1.4 to 1.6 s C. 1.5 to 1.6 s D. 1.6 to 1.8 s
Last Answer : D. 1.6 to 1.8 s
Description : A properly matched transmission line has a loss of 1.5 dB/100m. if 10 W is supplied to one end of the line, how many watts reach the load, 27 m away? A. 10 W B. 7.2 W C. 9.9 W D. 9.1 W
Last Answer : D. 9.1 W
Description : What is the term for the ratio of actual velocity at which a signal travels through a line to the speed of light in a vacuum? A. Velocity factor B. Characteristic impedance C. Surge impedance D. Standing wave ratio
Last Answer : A. Velocity factor
Description : What is the gain of an antenna over a half-wavelength dipole when it has 6 dB gain over an isotropic radiator? A. 6.0 dB B. 8.1 dB C. 3.9 dB D. 10.0 dB
Last Answer : C. 3.9 dB
Description : What is the optimum reverberation time at 500 Hz for a cinema? A. 0.8 – 1.2 sec. B. 0.9 – 1.3 sec. C. 0.6 – 0.8 sec. D. 0.45 – 0.55 sec.
Last Answer : A. 0.8 – 1.2 sec.
Description : Lightning rods must be mounted a top structure not less than ___ above the highest point. A. 10 cm B. 20 cm C. 30 cm D. 40 cm
Last Answer : C. 30 cm
Description : The international pitch A is equivalent to ___ Hz. A. 435 B. 440 C. 260 D. 255
Last Answer : A. 435
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 : At a certain time, the MUF for transmission at an angle of incidence of 75° is 17 MHz. What is the critical frequency? A. 4.4 MHz B. 3.5 MHz C. 6.5 MHz D. 1.5 MHz
Last Answer : A. 4.4 MHz
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 : 8096 has ___ general purpose I/O ports, Port 2 includes ______ of the following i) two quasi-bidirectional I/O lines ii) two output lines iii) four input lines iv) open drain outputs a) 4, i, iv b) 6, ii, iii c) 4, i,ii,iii d) 6, i, ii, iv
Last Answer : c) 4, i,ii,iii
Description : In 8096, mode ____ of serial port are ___ modes commonly used for ____ communications. a) 1, 8bit, single processor b) 0, 7bit, multiple microcontroller c) 2, 9 bit, multiple processors d) 3, 8 bit, multiple microcontroller
Last Answer : a) 1, 8bit, single processor
Last Answer : c) 2, 9 bit, multiple processors
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 : The standard deviation of the variation in the transmission loss of a circuit should not exceed A. 3 dB B. 1 dB C. 5 dB D. 0.5dB
Last Answer : B. 1 dB