Description : Fiber optic cables operate at frequencies near ∙ a. 20 MHz ∙ b. 200 MHz ∙ c. 2G Hz ∙ d. 800 THz
Last Answer : ∙ d. 800 THz
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 : 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 : 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 : What medium is used by IBM token ring network that operates at either 4 Mbps or 16 Mbps? A. Twisted pair B. Coaxial cable C. Fiber-optic D. Parallel-wire line
Last Answer : A. Twisted pair
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 : Fiber optic cables operate at frequencies near a. 20MHz b. 200MHz c. 2GHz d. 800THz
Last Answer : d. 800THz
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 : 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 : 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 : 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 : 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 : 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
Description : Atmospheric noise or static is not a great problem A. at frequencies below 20 MHz B. at frequencies below 5 MHz C. at frequencies above 30 MHz D. at frequencies above 1 MHz
Last Answer : C. at frequencies above 30 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 : 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 : 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 : 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 sky wave propagation? A. 30 to 300 kHz B. 3 MHz to 30 MHz C. 30 MHz to 300 MHz D. 3 GHz to 30 GHz
Last Answer : B. 3 MHz to 30 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 : 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 : Electromagnetic waves of frequencies arbitrarily lower than 3,000 GHz, propagated in space without artificial guide. A. Space waves B. Terrestrial waves C. Mobile D. Hertzian waves
Last Answer : D. Hertzian waves
Description : Which type of fiber-optic cable is the best for very high speed data? a. Single-mode step-index b. Multimode step-index c. Single-mode graded-index d. Multimode graded-index
Last Answer : a. Single-mode step-index
Description : Which type of fiber optic cable is most widely used? a. Single-mode step-index b. Multimode step-index c. Single-mode graded-index d. Multimode graded-index
Description : A popular light wavelength in fiber-optic cable is a. 0.7 um b. 1.3 um c. 1.5 um d. 1.8 um
Last Answer : b. 1.3 um
Description : Which of the following is not a major benefit of fiber-optic cable? a. Immunity from interference b. No electrical safety problems c. Excellent data security d. Lower cost
Last Answer : b. No electrical safety problems
Description : The core of a fiber optic cable is made of a. Air b. Glass c. Diamond d. Quartz
Last Answer : b. Glass
Description : Which of the following is not a common type of fiber-optic cable? a. Single-mode step-index b. Multimode graded-index c. Single-mode graded-index d. Multimode step-index
Last Answer : c. Single-mode graded-index
Description : The operation of the fiber-optic cable is based on the principle of a. Refraction b. Reflection c. Dispersion d. Absorption
Last Answer : b. Reflection
Description : Which of the following is not a common application of fiber-optic cable? a. Computer networks b. Long-distance telephone systems c. Closed circuit TV d. Consumer TV
Last Answer : d. Consumer TV
Description : Ho w many times bigger does the bandwidth of a fiber optic multimode have over a cable? A. 50 times bigger B. 100 times bigger C. 10 times bigger D. 5 times bigger
Last Answer : B. 100 times bigger
Description : If a fiber optic system has a rise time of 38.55 ns, the source rise time is 12 ns and the detector rise time is 12 ns, what is the cable rise time? A. 34.61 ns B. 14.55 ns C. 52.55 ns D. 26.25 ns
Last Answer : A. 34.61 ns
Description : If a fiber optic system has a rise time of 16 ns, the source rise time is 1.5 ns and the detector rise time is 2 ns, what is the cable rise time? A. 14 ns B. 6 ns C. 9 ns D. 12.5 ns
Last Answer : A. 14 ns
Description : ECE Board Exam March 1996 It is a spacecraft placed in orbit around the earth carrying onboard microwave receiver and transmitting equipments. A. Fiber optic equipment B. Communications satellite C. Wireless radio system D. Coaxial cable syste
Last Answer : B. Communications satellite
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 : 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 : 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 : Frequencies above ______ kHz, are referred to as the radio frequencies. A. 20 B. 2 C. 10 D. 200
Last Answer : A. 20
Description : The HFC network uses _______ cable. A) twisted-pair B) coaxial C) fiber-optic D) acombination of (b) and (c)
Last Answer : fiber-optic
Description : In a fiber-optic cable, the signal is propagatedalong theinner core by _______. A) reflection B) refraction C) modulation D) none of the above
Last Answer : reflection
Description : The bandwidth of optical fiber ∙ a. 900M Hz ∙ b. 900 PHz ∙ c. 900 THz ∙ d. 900 EHz
Last Answer : c. 900 THz
Description : A dielectric waveguide for the propagation of electromagnetic energy at light frequencies a. Stripline b. Microstrip c. Laser beam d. Fiber optics
Last Answer : d. Fiber optics
Description : When the elevation angle of a geostationary satellite is 23˚ and the transmitting frequency is 3840 MHz, what is the free space loss in dB? A. 196 dB B. 200 dB C. 150 dB D. 100 dB
Last Answer : A. 196 dB
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 : What is the required quality factor for an SSB filter with the following data: center frequency= 1 MHz, the desired attenuation level of the unwanted sideband= 80 dB and the separation between sidebands= 200 Hz? A. 1,250 B. 12,500 C. 125,000 D. 25,000
Last Answer : C. 125,000
Description : The following heat engine produces power of 100,000 kW. The heat engine operates between 800 K and 300 K. It has a thermal efficiency equal to 50% of that of the Carnot engine for the same temperature. The rate at which heat is ... is (A) 100,000 kW (B) 160,000 kW (C) 200,000 kW (D) 320,000 kW
Last Answer : (D) 320,000 kW
Description : The core of a fiber optic is surrounded by a. Wire braid shield b. Kevlar c. Cladding d. Plastic insulation
Last Answer : c. Cladding
Description : Photodiodes used as fiber optic directors are a. Unbiased to generate a voltage same as a solar cell b. Forward bias c. Reversed bias d. Thermoelectrically cooled
Last Answer : c. Reversed bias
Description : What is the device used in fiber optic communication which consist of a receiver transmitter use to clean up and amplify digital data moving in one direction and another in the opposite direction? A. Optic compressors B. Optic retarders C. Optic isolator D. Optic regenerators
Last Answer : D. Optic regenerators