Description : What is the free space loss, in dB, between two microwave parabolic antennas 38.0 kilometer apart operating at 7.0 GHz? A. 145.6 dB B. 138.5 dB C. 135.5 dB D. 140.89 dB
Last Answer : D. 140.89 dB
Description : What is the path attenuation between transmitter and receiver at a frequency of 1.2 Ghz and a distance of 11,000 mi? A. 119 dB B. 115dB C. 179dB D. 174dB
Last Answer : C. 179dB
Description : Part of a microwave link can be approximated by free space conditions. The antenna gain are each 40 dB, the frequency is 10 GHz, and the path length is 80 km. Calculate the receive power for a transmitted power of 10 W? A. 0.871 μW B. 871 μW C. 0.871 mW D. 871 nW
Last Answer : A. 0.871 μW
Description : The population of Pakistan according to 2017 Census is: A. 198 million B. 207 million C. 142.5 million D. 202 million
Last Answer : ANSWER: B
Description : Cable attenuation is usually expressed in terms of a. Loss per foot b. dB/km c. intensity per mile d. voltage drop per inch
Last Answer : b. dB/km
Description : The frequency of Ku band for satellite communications. A. 6/4 GHz B. 14/11 GHz C. 12/14 GHz D. 4/8 GHz
Last Answer : B. 14/11 GHz
Description : What is the current frequency band given most attenuation for satellite communications? A. Ku B. C band C. J D. P
Last Answer : A. Ku
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 total space loss of transmission and reception for two ground stations with uplink frequency 8GHz and a downlink of 6 GHz with angle of elevations of 3˚ and 7˚ A respectively is A. 403 dB B. 100 dB C. 20 dB D. 215 dB
Last Answer : A. 403 dB
Description : What frequency does oxygen causes excessive attenuation A. 119 GHz B. 183 GHz C. 310 GHz D. 60 GHz
Last Answer : D. 60 GHz
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 : What is the quardband between transponder channels in the commercial C-band for satellite communications? A. 6 MHz B. 36 MHz C. 4 MHz D. 2 MHz
Last Answer : C. 4 MHz
Description : Determine the terrain sensitivity loss for a 4-GHz carrier that is propagating over a very dry, mountainous area. A. -1.25 dB B. -3.05 dB C. -2.01 dB D. -5.01 dB
Last Answer : A. -1.25 dB
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 : ECE Board Exam November 1996 What is the applied power if a thermal RF wattmeter is connected to a transmitter through a variable attenuator? The wattmeter reads 84 mW when 15 dB of attenuation is used. A. 4.656 watts B. 2.656 watts C. 3.656 watts D. 2.856 watts
Last Answer : B. 2.656 watts
Last Answer : A. PAM
Description : The altitudinal distance of a geostationary satellite from the earth is about: (A) 26,000 km (B) 30,000 km (C) 36,000 km (D) 44,000 km
Last Answer : Answer: Option C
Description : Satellite system or part of a satellite system, consisting of only one satellite and the operating earth station. A. Satellite system B. Satellite network C. Space system D. Multi-satellite link
Last Answer : B. Satellite network
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 : What is the approximate path loss from satellite-to-earth station? A. 100 dB B. 150 dB C. 175 dB D. 200 dB
Last Answer : D. 200 dB
Description : Electromagnetic wave travel at __________ in free space. A. 300,000 km/sec B. 100,000 km/ sec C. 400,000 km/sec D. 200km/sec
Last Answer : A. 300,000 km/sec
Description : Cable attenuation is usually expressed in terms of ∙ A. loss per foot ∙ B. dB/km ∙ C. intensity per mile ∙ D. voltage drop per inch
Last Answer : . dB/km
Description : A fiber-optic cable has a loss of 15 dB/km. The attenuation in a cable 1000 ft. long is ∙ A. 4.57 dB ∙ B. 9.3 dB ∙ C. 24 dB ∙ D. 49.2 dB
Last Answer : A. 4.57 dB
Description : . A fiber-optic cable has a loss of 15 dB/km. The attenuation in a cable, 100 ft long is ∙ a. 4.57 dB ∙ b. 9.3 dB ∙ c. 24 dB ∙ d. 49.2 dB
Last Answer : ∙ a. 4.57 dB
Description : Cable attenuation is usually expressed in terms of ∙ a. Loss per foot ∙ b. dB/km ∙ c. intensity per mile ∙ d. voltage drop per inch
Last Answer : ∙ b. dB/km
Description : (1675÷5) + (5328÷12) * (8430÷15) = ?2 – 235 a) 152 b) 138 c) 158 d) 142 e) None of these
Last Answer : 335+444*56 = 24864+335 = 25199 – 235 = 24964 158*158 = 24964 Answer: c)
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 : The Ku-band in the satellite service A. 14/11 GHz B. 30/17 GHz C. 8/7 GHz D. 6/4 GHz
Last Answer : A. 14/11 GHz
Description : A receiver is located 64 km from a space wave transmitting antenna that is 100 meters high. Find the required height of the receiving antenna. A. 36 meters high B. 64 meters high C. 100 meters high D. 182.25 meters high
Last Answer : A. 36 meters high
Description : Which of the cable length has the highest attenuation? a. 1 km b. 2 km c. 95 ft d. 5500 ft
Last Answer : b. 2 km
Description : Which of the following phenomena is possible is free space medium? A. Reflection of radio wave B. Diffraction of radio wave C. Refraction of radio wave D. Attenuation of radio wave
Last Answer : D. Attenuation of radio wave
Description : The height of a geo-stationary satellite from the Earth's surface is approximately : (1) 36,000 km (2) 42,000 km (3) 30,000 km (4) None of these
Last Answer : (1) 36,000 km Explanation: A geostationary orbit is a circular orbit 35,786 kilometres above the Earth's equator and following the direction of the Earth's rotation. Communications satellites and weather ... to track them, but can be pointed permanently at the position in the sky where they stay.
Description : The height of a geo-stationary satellite from the Earth’s surface is approximately : (1) 36,000 km (2) 42,000 km (3) 30,000 km (4) None of these
Last Answer : 36,000 km
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 : A choir consisting of 36 individuals all of whom can sing with the same intensity. A soloist sings a certain passage and then is joined by the remainder of the choir members for a repeat of the passage. What is the ... sound intensity level in the two cases? A. 3 dB B. 6 dB C. 36 dB D. 15.6dB
Last Answer : D. 15.6dB
Description : How does the gain of a parabolic dish type antenna change when the operating frequency is doubled? A. Gain does not change B. Gain is multiplied by 0.707 C. Gain increases 6 dB D. Gain increases 3 dB
Last Answer : C. Gain increases 6 dB
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 : 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 key electronic component in a communications satellite is the A. telemetry equipment B. on-board computer C. command and control system D. transponder
Last Answer : D. transponder
Description : One of the first satellite system catering personal based communications services scheduled for operation. A. Iridium system B. Plutonium system C. Indium system D. Gallium system
Last Answer : A. Iridium system
Description : The sound power level of a jet plane flying at a height of 1 km is 160 dB. What is the maximum sound pressure level on the ground directly below the plane assuming that the aircraft radiates sound equally in all directions? A. 59.1 dB B. 69.1 dB C. 79.1 dB D. 89.1 dB
Last Answer : D. 89.1 dB
Description : What is the data rate in Mbps of a single satellite transponder considering an S/N of 30 dB? A. 35.8 B. 3.58 C. 358 D. 3580
Last Answer : C. 358
Description : A radio communications link is to be established via the ionosphere. The maximum virtual height of the layer is 100 km at the midpoint of the path and the critical frequency is 2 MHz. The distance between stations is 600 ... optimum working frequency? A. 6.32 MHz B. 2.1 MHz C. 5.4 MHz D. 1.8 MHz
Last Answer : C. 5.4 MHz
Description : Which does not use vertical polarization antenna? A. AM Broadcasting B. FM Broadcasting C. Mobile Communications D. Satellite Communications
Last Answer : B. FM Broadcasting
Description : Which of the following is the most common application of satellite? A. Surveillance B. Military application C. Communications D. Newscasting
Last Answer : C. Communications
Description : The satellite communications channels in a transponder are defined by the A. LNA B. bandpass filter C. mixer D. input signals
Last Answer : B. bandpass filter
Description : The satellite subsystem that monitors and controls the satellite is the A. propulsion subsystem B. power subsystem C. communications subsystem D. telemetry, tracking, and command subsystem
Last Answer : D. telemetry, tracking, and command subsystem