Description : Tropospheric scatter is a method of sky wave propagation for which of the following frequency bands? A. 300 kHz to 3 MHz B. 3 MHz to 30 MHz C. 30 MHz to 300 MHz D. 300 MHz to 3 GHz
Last Answer : D. 300 MHz to 3 GHz
Description : Which of the following frequency bands is best suited for ground wave propagation? A. 30 to 300 kHz B. 300 kHz to 3 MHz C. 3 MHz to 30 MHz D. 30 MHz to 300 MHz
Last Answer : A. 30 to 300 kHz
Description : The extremely high frequency (EHF) band is in the radio spectrum range of _______. A. 30 to 300 kHz B. 30 to 300 GHz C. 3 to 30 MHz D. 3 to 30 GHz
Last Answer : B. 30 to 300 GHz
Description : Industrial noise frequency is between _________. A. 200 to 3000 Mhz B. 15 to 160 Mhz C. 0 to 10 Khz D. 20 Ghz
Last Answer : B. 15 to 160 Mhz
Description : Most satellites operate in which frequency band? A. 30 to 300 MHz B. 300 MHz to 3 GHz C. 3 GHz to 30 GHz D. Above 300 GHz
Last Answer : C. 3 GHz to 30 GHz
Description : A voice-grade circuit using the PTN has an ideal passband of A. 0 to 4 Hz B. 0 to 4 kHz C. 0 to 4 GHz D. 0 to 4 MHz
Last Answer : B. 0 to 4 kHz
Description : The band of frequencies least susceptible to atmospheric noise and interference is: A. 30 – 300 kHz B. 300 – 3000 kHz C. 3 – 30 MHz D. 300 – 3000 MHz
Last Answer : D. 300 – 3000 MHz
Description : What is the frequency of a 2-cm sound wave in sea water at 25˚C? A. 76 kHz B. 76 Hz C. 76 MHz D. 76 mHz
Last Answer : A. 76 kHz
Description : Coaxial lines are used on those systems operating _______. A. Below 2 GHz B. At 300 MHz C. Above 10KHz D. Above 10GHz
Last Answer : A. Below 2 GHz
Description : What frequency range is used for FM radio transmission? A. Very Low Frequency : 3 kHz to 30. kHz B. Low Frequency :30 kHz to 300 kHz C. High Frequency :3 MHz to 30 MHz D. Very High Frequency : 30 MHz to 300 MHz E. None of the above
Last Answer : Very High Frequency : 30 MHz to 300 MHz
Description : The bandwidth of C-band satellite frequency band in U.S. A. 500 GHz B. 1000 GHz C. 1000 MHz D. 500 MHz
Last Answer : D. 500 MHz
Description : What is the local oscillator (mixer) frequency of the satellite with an uplink frequency in GHz band? A. 3500 MHz B. 4500 MHz C. 2225 MHz D. 2555 MHz
Last Answer : C. 2225 MHz
Description : A radio frequency in the ultra high frequency band of the radio spectrum band. A. 235.50 MHz B. 450.50 MHz C. 150.50 GHz D. 0.31250 GHz
Last Answer : D. 0.31250 GHz
Description : To obtain the most reliable sky wave propagation the ____ should be used. A. Lowest useable frequency (LUF). B. Maximum useable frequency (MUF). C. Optimum useable frequency (OUF). D. Critical frequency
Last Answer : C. Optimum useable frequency (OUF).
Description : Signals with a frequency between 2 MHz and 30 MHz use ______ propagation. A) ground B) sky C) line-of-sight D) none of the above
Last Answer : sky
Description : Atmospheric noise is less at severe frequencies above A. Audio level B. 30 MHz C. 10 GHz D. 1 GHz
Last Answer : B. 30 MHz
Description : What frequency is 10 octaves above 30 Hz? A. 30.72 kHz B. 30 kHz C. 300 Hz D. 307.2 kHz
Last Answer : A. 30.72 kHz
Description : Industrial noise frequency is between _____. A. 0 to 10 KHz B. 160 MHz to 200 MHz C. 15 to 160 MHz D. 200 to 3000 MHz
Last Answer : C. 15 to 160 MHz
Description : Assuming a UHF frequency range of 405.0125 MHz to 405.0875 MHz at 25 kHz channeling plan, how many channels can you produce? A. 2.5 ch. B. 2 ch. C. 4 ch. D. 3 ch.
Last Answer : D. 3 ch.
Description : Assume a frequency range of 405.0125 MHz to 405.0875 MHz and 25 kHz channeling plan, determine the center frequency of the second channel from the lower limit. A. 405.030 MHz B. 405.025 MHz C. 405.050 MHz D. 405.075 MHz
Last Answer : C. 405.050 MHz
Description : Assume a frequency range of 401.000 MHz to 401.050 MHz, if you apply 25 kHz channeling plan, determine the center frequency of the first channel from the lower limit. A. 401.010 MHz B. 401.0125 MHz C. 401.025 MHz D. 401.00625 MHz
Last Answer : B. 401.0125 MHz
Description : Atmospheric noise becomes less severe at frequencies A. above 30 MHz B. below 30 MHz C. above 3000 kHz D. below 3000kHz
Last Answer : A. above 30 MHz
Description : What is the spectrum of stereophonic FM signal? A. 19 to 38 kHz B. 30 to 53 kHz C. 59.5 to 74.5 kHz D. 88 to 108 MHz
Last Answer : B. 30 to 53 kHz
Description : Which of the following is designated as the international distress, safety and calling frequency for radio telephony for stations of the maritime mobile service when using frequencies in the authorized bands between 156 and 174 MHz? A. 165.8 MHz B. 156.8 MHz C. 158.6 MHz D. 168.5 MHz
Last Answer : B. 156.8 MHz
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 : Which of the following statements is not true with respect to microwaves? (A) Electromagnetic waves with frequencies from 300 GHz to 400 THz. (B) Propagation is line-of-sight. (C) Very ... waves cannot penetrate walls. (D) Use of certain portions of the band requires permission from authorities.
Last Answer : (A) Electromagnetic waves with frequencies from 300 GHz to 400 THz.
Description : The 2G GSM technology uses a carrier separation of _____________ a) 1.25 MHz b) 200 KHz c) 30 KHz d) 300 KHz
Last Answer : b) 200 KHz
Description : Extra-terrestrial noise is observable at frequencies from A. 0 to 20 KHz B. Above 2 GHz C. 8 to 1.43 GHz D. 5 to 8 GHz
Last Answer : C. 8 to 1.43 GHz
Description : Signals with a frequency below 2 MHz use _______ propagation. A) ground B) sky C) line-of-sight D) none of the above
Last Answer : ground
Description : What noise is observable at frequencies in the range from about 8 MHz to somewhat 1.5 GHz? A. Industrial noise B. Atmospheric noise C. Space noise D. Shot noise
Last Answer : C. Space noise
Description : What noise type is observable between 8 MHz to somewhat above 1.43 GHz or up to 1.5 GHz? A. Solar noise B. Space noise C. Galactic noise D. Cosmic noise
Last Answer : B. Space noise
Description : Fiber optic cable operates near _______ frequencies. A. 800 THz B. 20 MHz C. 200 MHz D. 2 GHz
Last Answer : A. 800 THz
Description : What is the approximate bandwidth of an FM system with 10 kHz of modulating frequency and a 150 kHz of frequency deviation? A. 300 kHz B. 320 kHz C. 150 kHz D. 200 kHz
Last Answer : B. 320 kHz
Description : What is the baseband frequency of standard FDM basic supergroup? A. 312 to 552 kHz B. 300 to 600 kHz C. 60 to 2540 kHz D. 60 to 108 kHz
Last Answer : A. 312 to 552 kHz
Description : The rhombic antenna is primarily used for A. ground wave propagation B. space wave propagation C. ionosphere scatter propagation D. sky wave propagation
Last Answer : D. sky wave propagation
Description : Which of the following layers of the ionosphere has no effect on sky wave propagation during daytime? A. D B. E C. F1 D. F2
Last Answer : A. D
Description : The decimetric wave is using what method of propagation? A. Ground wave B. Space wave C. Sky wave D. Tropospheric wave
Last Answer : B. Space wave
Description : Which if the following layers of the ionosphere has no effect on sky wave propagation during the hours of darkness? A. D B. E C. F1 D. F2
Description : ECE Board Exam March 1996 When the transmitting and receiving antennas are in line-of-sight of each other, the mode of propagation is ________ wave. A. space or direct B. ground C. surface D. sky
Last Answer : A. space or direct
Description : A 1 Mhz carrier is amplitude modulated by a pure 200-Hz audio test tone. Which of the following combinations of frequencies represent the total content of the AM signal? A. 1 MHz and 200 Hz B. 1 MHz and 1000.2 kHz C. 999.8 kHz, 1000 kHz, and 1000.2 kHz D. 999.8 kHz and 1000.2 kHz
Last Answer : C. 999.8 kHz, 1000 kHz, and 1000.2 kHz
Description : How many voice signals (4 kHz max.) would fit into a 5 MHz spectrum? A. 1250 B. 500 C. 1000 D. 1500
Last Answer : A. 1250
Description : For a 300-m optical fiber cable with a bandwidth distance product of 600 MHz-km, determine the bandwidth. ∙ A. 5 GHz ∙ B. 1 GHz ∙ C. 2 GHz
Last Answer : C. 2 GHz
Description : For a sample rate of 40 kHz, determine the maximum analog input frequency A. 30 kHz B. 40 kHz C. 20 kHz D. 10 kHz
Last Answer : C. 20 kHz
Description : The frequency spectrum of the stereophonic FM signal. A. 67 kHz B. 59.5 to 74.5 kHz C. 19 to 38 kHz D. 30 to 53 kHz
Last Answer : D. 30 to 53 kHz
Description : A pulse radar has a pulse repetition frequency (PRF) of 3 KHz. If the radar is emitting at 10 GHz, what is the maximum unambiguous range for this radar? A) 5 Km B) 5 m C) 50 Km D) 15 m
Last Answer : A pulse radar has a pulse repetition frequency (PRF) of 3 KHz. If the radar is emitting at 10 GHz, what is the maximum unambiguous range for this radar? A) 5 Km B) 5 m C) 50 Km D) 15 m
Description : What is the most commonly used intermediate frequency of radar receivers? A. 40 MHz B. 60 MHz C. 70 MHz D. 30 MHz
Last Answer : D. 30 MHz
Description : This type of transmission permits communication in the frequency range from 30 to 60 MHz and over distances from about 1000 to 2000 km. A. Troposcatter B. Ionospheric scatter C. Ducting D. Microwave
Last Answer : B. Ionospheric scatter
Description : Type of transmission path that permits communication in the frequency range from 30 to 60 MHz and over distances form about 1000 to 2000 km. A. Ducting B. Ionospheric scatter C. Microwave D. Troposcatter
Description : If a carrier wave of 1000 kHz is used to carry the signal, the length of transmitting antenna will be equal to _______. (1) 300 m (2) 30 m (3) 3 m (4) 0.3 m
Last Answer : (1) 300 m Explanation: h = 3 × 108/106 = 300 m
Description : Approximately what is the frequency limit of the optical fiber? ∙ A. 20 MHz ∙ B. 1 MHz ∙ C. 100 MHz ∙ D. 40 GHz
Last Answer : ∙ D. 40 GHz