Description : What band of frequencies do these satellites operate? A. L band B. Ka band C. C band D. Ku band
Last Answer : A. L band
Description : For navigation as well as marine and aeronautical communications and radar, ____ band is used. A. L B. K C. S D. J
Last Answer : A. L
Description : A band where most military satellite often operate A. Ku B. C C. X D. L
Last Answer : C. X
Description : Most commercial satellite activity occurs in which band(s)? A. L B. C and Ku C. X D. S and P
Last Answer : B. C and Ku
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 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 : Emission on a frequency or frequencies immediately outside the necessary bandwidth which result from the modulation process except spurious emission. A. Radiation B. Noise C. Out of the band D. Interference
Last Answer : C. Out of the band
Description : Troposheric scatter uses the frequencies in the ________ band. A. VLF B. UHF C. VHF D. UF
Last Answer : B. UHF
Description : The ___________ filter attenuates signals but passes frequencies below and above that band. A. low pass B. band pass C. band stop D. high pass
Last Answer : C. band stop
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 : What band does VSAT first operate? A. L-band B. X-band C. C-band D. Ku-band
Last Answer : C. C-band
Description : ____ system transmits frequency-division-multiplexed voice band signals over a coaxial cable for distances up to 4000 miles. A. T carrier B. X carrier C. L carrier D. F carrier
Last Answer : C. L carrier
Description : A band whereloften operate A. Ku B. C C. X D. L
Description : What band does VSAT first operate? A. X-band B. C-band C. Ku-band D. L-band
Last Answer : B. C-band
Description : Which one of the following statements is correct regarding the GPS satellites? (A) The nominal altitude is about 20,200 km (B) The inclination of axis satellite is 55° (C) The satellite transmits two L band signals (L1 with 1575.42 MHz and L2 with 1276.6 MHz) (D) All of these
Last Answer : Answer: Option D
Description : First communication satellites used frequencies of A. 6 GHz for uplink B. 3 GHz for uplink C. 6 GHz for downlink D. 5 GHz for downlink
Last Answer : 6 GHz for uplink
Description : Radar is used to (1) locate submerged submarines. (2) receive signal from radio receivers. (3) detect and locate distant objects. (4) locate geostationary satellites.
Last Answer : detect and locate distant objects
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 IF frequencies are normally used in radar receivers
Last Answer : Thirty or sixty megahertz.
Description : Geostationary stationary satellites are located ___________ with respect to the equator. A. 0˚longitude B. 0˚ latitude C. 90˚latitude D. 45 latitude˚
Last Answer : B. 0˚ latitude
Description : What kind of battery used by older satellites? A. Lithium B. Leclanche C. Hydrogen D. Magnesium
Last Answer : C. Hydrogen
Description : Repeaters inside communications satellites are known as A. Trancievers B. Transponders C. Transducers D. TWT
Last Answer : B. Transponders
Description : An automated ship-to-shore distress alerting system using satellites and advanced terrestrial communications systems. A. GPS B. Iridium system C. INMARSAT D. GMDSS
Last Answer : D. GMDSS
Description : What is the orbit inclination of geostationary satellites? A. 0° B. 10° C. 20° D. 30°
Last Answer : A. 0°
Description : Iridium satellites can provide data communications of up ____ bps data rate. A. 1200 B. 4800 C. 2400 D. 3840
Last Answer : C. 2400
Description : What is the typical center frequency spacing between adjacent channels (transponders) in satellites? A. 36 MHz B. 40 MHz C. 500 MHz D. 4 MHz
Last Answer : B. 40 MHz
Description : The most common application of satellites A. Surveillance B. Reconnaissance C. Defense systems D. Communication
Last Answer : D. Communication
Description : In satellite communication, the Geostationary satellites are conveniently located with respect to the equator at _______. A. 45 degrees latitude B. 90 degrees latitude C. 0 degrees latitude D. 5 degrees latitude
Last Answer : C. 0 degrees latitude
Description : What kind of battery panels are used in some advance satellites? A. Gallium Arsenide solar panel B. Germanium based panels C. Silicon based panels D. Gallium Phosphate solar panel
Last Answer : A. Gallium Arsenide solar panel
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 : Fiber optic cables operate at frequencies near a. 20MHz b. 200MHz c. 2GHz d. 800THz
Last Answer : d. 800THz
Description : A disadvantage of using a trap antenna. A. It will radiate harmonics B. It can only be used for single-bad operation C. It is too sharply directional at lower frequencies D. It must be neutralized
Last Answer : A. It will radiate harmonics
Description : In what range of frequencies are most omnidirectional horizontally polarized antennas used? A. VHF, UHF B. VLF, LF C. SH, EHF D. MF, HF
Last Answer : A. VHF, UHF
Description : How can multiple earth stations share a satellite on the same frequencies? A. Frequency reuse B. Multiplexing C. Mixing D. Frequency hopping
Last Answer : A. Frequency reuse
Description : Which of the following low noise transistors is commonly used at microwave frequencies? A. MOSFET B. GASFET C. MESFET D. JFET
Last Answer : C. MESFET
Description : Which of the following types of noise becomes of great importance at frequencies? A. Shot noise B. Random noise C. Impulse noise D. Transit-time noise
Last Answer : D. Transit-time noise
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 : 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 : Which of the following frequencies is normally used for distress and safety communications? A. 4209.5 kHz B. 490 kHz C. 518 kHz D. 2174.5 kHz
Last Answer : D. 2174.5 kHz
Description : What is the channel spacing for SITOR frequencies? A. 500 Hz B. 170 Hz C. 300 Hz D. 3 kHz
Last Answer : A. 500 Hz
Description : What is the channel spacing for MF-HF voice frequencies? A. 2.8 kHz B. 500 Hz C. 3.5 kHz D. 3 kHz
Last Answer : D. 3 kHz
Description : The American concert pitch A is equivalent to which if the following frequencies? A. 440 Hz B. 435 Hz C. 260 Hz D. 255 Hz
Last Answer : A. 440 Hz
Description : A porous material is far more efficient at high than low frequency absorption. How to improve sound absorption at lower frequencies using this absorber? A. Increase the thickness B. Decrease the thickness C. Mount with and airspace behind D. Both A and C above
Last Answer : D. Both A and C above
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 : In cellular system, _____ defines the geographic distance that is required between cells using identical frequencies in order to avoid interference between the radio transmissions at these cells. A. frequency-reuse ratio B. distance-to-reuse ratio (D/R) C. reuse format plan ratio D. reuse factor
Last Answer : B. distance-to-reuse ratio (D/R)
Description : What device measures the angle between two radio frequencies and also the direction of propagation of a wave? A. Densimeter B. Absorption wavemeter C. Goniometer D. Ergometer
Last Answer : C. Goniometer
Description : When no signal is being received, the loudspeaker is not entirely silent as a result of the presence of A. parasitic oscillations in some of the receiver stages. B. negative feedback in each stage. C. spurious frequencies as a result of improper neutralization. D. internal receiver noise.
Last Answer : D. internal receiver noise.
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 : The ratio of frequencies is termed. A. interval B. octave C. harmonics D. factor
Last Answer : A. interval
Description : Frequencies above ______ kHz, are referred to as the radio frequencies. A. 20 B. 2 C. 10 D. 200
Last Answer : A. 20