Description : For a space wave transmission, the radio horizon distance of a transmitting antenna with a height of 100 meters is approximately: A. 10 km B. 40 km C. 100 km D. 400 km
Last Answer : B. 40 km
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 : What is the maximum line-of-sight distance between a paging antenna 250 ft high and a pager receiver 3.5ft of the ground? A. 25 km B.25mi C. 70.73 km D. 70.73 mi
Last Answer : B.25mi
Description : A satellite transmitter operates at 4GHz with an antenna gain of 4dBi. The receiver 40000 km away has an antenna gain of 50 dBi. If the transmitter has a power of 8 W, find (ignoring feedline losses and mismatch) the EIRP in dBW. A. 50 B. 69 C. 49 D. 30
Last Answer : C. 49
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 : What phenomenon causes the radio-path horizon distance to exceed the geometric horizon? A. Diffraction B. Ducting C. Reflection D. Refraction
Last Answer : D. Refraction
Description : What phenomenon causes the radio-path horizon distance to exceed the geometric horizon? A. E-layer skip. B. D-layer skip. C. Auroral skip. D. Radio waves may be bent.
Last Answer : D. Radio waves may be bent.
Description : Karthiga jogs a speed of 18 km/hr at a distance of 27 km. at what speed would she need to jog during the next 4.5 hrs to have an average of 27km/hr for the entire jogging session. a) 40km/hr b) 30 km/hr c) 20 km/hr d) 35 km/hr
Last Answer : B Let the speed of jagging be x km/hr Total time taken = (27/18 hrs + 4.5 hrs) =(1.5 hrs + 4.5 hrs) =6 hrs Total distance covered = (27+4.5 x) km Therefore (27 +4.5x) / 6= 27 27+4.5x = 162 4.5x = 135 X=135/4.5 =30 So jagging speed is 30 km/hr
Description : The rajdhani express of 400m runs at a speed of 124 km/hr and a person runs on the platform at a speed of 40km/hr in the direction opposite to that of the train. Find the time taken by the train to cross the running person? A) 7 sec B) 8.78sec C) 7.78sec D) 8 sec
Last Answer : ANSWER : B Explanation: Length of the train = 400m Speed of train = 124 km/hr Speed of person = 40 km/hr Relative speed (speed of trai relative to man) = (124 + 40) km/hr = 164 km/hr [As the ... train to cover 400m at a relative of 45.55 m/s = 400 / 45.55 = 8.78 sec.
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 : If a transmitting antenna is 100 meters high and a separate receiving antenna is 64 meters high, what is the maximum space wave communication distance possible between them? A. 18 km B. 72 km C. 164 km D. 656 km
Last Answer : B. 72 km
Description : What is the orbit height of a GPS satellite? A. 10,898 nmi B. 10,898 mi C. 10,898 km D. 10, 898 m
Last Answer : A. 10,898 nmi
Description : Which of the following statements is an interpretation of the METAR? 00000KT 0200 R14/0800U R16/P1500U FZFG VV001 m03/m03 Q1022 BECMG 0800 = a. Meteorological visibility 200m, RVR for ... 800m, vertical visibility 100ft, calm, meteorological visibility improving to 800m in the next 2 hours
Last Answer : d. RVR for runway 14 800m, vertical visibility 100ft, calm, meteorological visibility improving to 800m in the next 2 hours
Description : Which of the following statements is an interpretation of the METAR? 00000KT 0200 R14/0800U R16/P1500U FZFG VV001 m03/m03 Q1022 BECMG 0800 = a. Meteorological visibility 200m, RVR for ... 14 800m, vertical visibility 100ft, calm, meteorological visibility improving to 800m in the next 2 hours
Description : The angle of elevation of the antenna beam is 20°. Calculate the transmission-path distance for an ionospheric transmission that utilizes a layer of virtual height 200 km. Use flat-earth approximation. A. 966 km B. 2100 km C. 1100 km D. 405 km
Last Answer : C. 1100 km
Description : A final amplifier of a radio transmitter draws 250 mA of plate current when the plate supply voltage is 1400 volts. If the plate circuit efficiency is 80% and the transmitter is connected to an antenna having a feed impedance of 70 ohms, ... at the feed-point? A. 4.0 A B. 2.2 A C. 1.25 A D. 2.0 A
Last Answer : D. 2.0 A
Description : The polarization of a radio wave: A. Is perpendicular to the electrostatic field of the antenna B. Is the same direction as the electrostatic field of the antenna. C. Is the same direction ... field of the antenna. D. Is perpendicular to both the electrostatic and magnetic fields of the antenna.
Last Answer : B. Is the same direction as the electrostatic field of the antenna.
Description : What type of transmission is radiated from an aircraft’s radio altimeter antenna? A. An amplitude modulated continuous wave B. A pulse position modulated UHF signal C. A differential phase shift keyed UHF signal D. A frequency modulated continuous wave
Last Answer : D. A frequency modulated continuous wave
Description : Type of emission produced by one of the early radio transmitter in trains of damped RF ac waves where its oscillator is coupled to a long wire antenna, normally used in radio telegraph and having sidebands on its carrier. A. Digital emission B. Key emission C. Cycle emission D. Spark emission
Last Answer : D. Spark emission
Description : It is an average power of a radio transmitter supplied to the antenna transmission line taken during a long sufficient interval of time and compared with the lowest frequency encountered in the modulation ... operating conditions. A. Carrier power B. Rated power C. Mean power D. Peak envelop power
Last Answer : C. Mean power
Description : Which of the following parts of the radio receiver represent the component that extracts the desire RF signal from the electromagnetic wave? A. AF amplifier B. Antenna C. Detector D. Crystal
Last Answer : B. Antenna
Description : What is a dummy antenna? A. One which is used as a reference for gain measurements B. And antenna used for hand-held radio C. An non-directional transmitting antenna D. A non-radiating load for a transmitter used for testing
Last Answer : D. A non-radiating load for a transmitter used for testing
Description : Referred to as an average power from the radio transmitter supplied to the antenna transmission line taken during one radio frequency cycle under no modulation. A. Carrier power B. Rated power C. Peak envelop power D. Mean power
Last Answer : A. Carrier power
Description : Radio wave concentration in the direction of the signal emitted by a directional antenna. A. Back lobe radiation B. Side lobe radiation C. Major lobe radiation D. Transmitted signal
Last Answer : C. Major lobe radiation
Description : Average power of a radio transmitter supplied to the antenna transmission line by a transmitter during one radio frequency cycle taken under the condition of no modulation. A. Peak envelop power B. Rated power C. Carrier power D. Mean power
Last Answer : C. Carrier power
Description : How far away can the aided eye see in a level line to the horizon?
Last Answer : I heard 25 miles.
Description : What is the seventh harmonic of a 100 MHz quarter wavelength antenna? A. 14.28 MHz B. 107 MHz C. 149 MHz D. 700 MHz
Last Answer : D. 700 MHz
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 : Determine the effective radiated power of 20 kW TV broadcast transmitter whose antenna has a field gain of 2. A. 40 kW B. 80,000 watts C. 40,000 watts D. 8,000 watts
Last Answer : B. 80,000 watts
Description : A satellite position is measured by its __________ angle with respect to the horizon. A. elevation B. depression C. azimuth D. critical
Last Answer : A. elevation
Description : An object on the top of a hill 100 m high is just visible above the horizon from a station at sea level. The distance between the station and the object is : (a) 38.53 km (b) 3.853 km (c) 3853 km (d) 385.3 km
Last Answer : (a) 38.53 km
Description : A positive lens with a focal length of 10 cm forms a real image of an object 20 am away from the lens. How far is the real image from the lens? a. 5 cm b. 10 cm c. 15 cm d. 20 cm
Last Answer : d. 20 cm
Description : An aircraft has to communicate with a VHF station at a range of 300nm, if the ground station is situated 2,500ft amsl, which of the following is the lowest altitude at which contact is likely to be made? a. 190ft b. 1,378ft c. 36,100ft d. 84,100ft
Last Answer : c. 36,100ft
Description : The sound intensity received from the nearby jet plane is 12.6 µW/m2 and that from another jet plane some distance away is 0.45 µW/m2 . Find the relative loudness of the two. A. 14.0 dB B. 14.5dB C. 12.5 D. 14.5
Last Answer : B. 14.5dB
Description : Three identical circuits having 10 dB signal noise-to-noise ratio each are connected in tandem with each other, what is the overall S/N? A. 5.23 dB B. 14.77dB C. 30 dB D. 40 dB
Last Answer : A. 5.23 dB
Description : Two automobiles are 150 kilometers apart and traveling toward each other. One automobile is moving at 60km/h and the other is moving at 40km/h mph. In how many hours will they meet? A. 2.5 B. 2.0 C. 1.75 D. 1.5 (Answer) E. 1.25
Last Answer : D. 1.5 (Answer)
Description : Arun steals a van at 8.30 am and drives it at 40km/hr. The theft is discovered at 9 a.m and the owner sets off in another van at 55km/hr. when will he overtake arun? a) 10.20 am b) 12.20am c) 11.20am d) 10.15am
Last Answer : A Suppose the arin is overtaken x hrs after 8.30 a.m Then distance covered by arun in x hrs = distance covered by the owner in(x-1/2) hrs 40x =55(x-1/2) 40x = 55x -55/2 55x – 40x =55/2 15x=55/2 X = 55/2*1/15 x=55/30 x= 1hr 50mins so the thief is overtaken at 10.20 a.m
Description : A van travels from namakkal to Madurai at a constant speed. If its speed were increased by 40km/hr it would have taken 1 hr lesser to cover the distance. It would have taken further 45 mins lesser if the speed ... by 40km/hr. what is distance between the 2 cities. a) 1680 b) B1660 c) 1670 d) 1675
Last Answer : A Let distance = x km Usual rate = y km/hr Then x/y - x/(y+40) =1 X(y+40) / y(y+40) = 1 Xy+40x - xy = y(y+40) 40x = y(y+40) ---------->1 x/y - x/y+80 = 7/4 x(y+80) - xy / y(y+ ... (y+80) / y(y+40) 8(y+40) = 7y + 560 8y +320 = 7y+560 Y=240 Substitute y value in 1 40x = 240*280 X=1680 km
Description : An isotropic radiator is A. in the northern hemisphere B. an antenna high enough in the air C. an antenna whose directive pattern is substantially incredible D. a hypothetical, omnidirectional antenna
Last Answer : D. a hypothetical, omnidirectional antenna
Description : Harmonic suppressor connected to an antenna. A. Low-pass filter B. High-pass filter C. M-derived filter D. Constant-K
Last Answer : A. Low-pass filter
Description : An antenna with very high gain and very narrow beamwidth. A. Helical antenna B. Discone antenna C. Horn antenna D. Parabolic dish antenna
Last Answer : D. Parabolic dish antenna
Description : A device that converts high frequency current into electromagnetic wave. A. Antenna B. Loudspeaker C. Microphone D. Transducer
Last Answer : A. Antenna
Description : How can intermodulation interference between two transmitters in close proximity reduced or eliminated? A. Through installing a band-pass filter in the antenna feed line B. Through installing terminated circulator ... high driving power D. By installing a low-pass filter in the antenna feed line
Last Answer : A. Through installing a band-pass filter in the antenna feed line
Description : Harmonic suppressor connected to an antenna. A. High pass filter B. Low pass filter C. Tank circuit D. M-derived filter
Last Answer : B. Low pass filter
Description : The speed of light is a. 186,000 mi/h b. 300 mi/h c. 300,000 m/s d. 300,000,000 m/s
Last Answer : d. 300,000,000 m/s
Description : What is the height of a satellite in a synchronous equatorial orbit? A. 42000 mi B. 6800 mi C. 22,300 mi D. 35,860 mi
Last Answer : C. 22,300 mi
Description : The noise from an airplane engine 100 ft from an observer is found to have an intensity of 45dB. What will be the intensity when the plane flies overhead at an altitude of 1 mi? A. 10.5 dB B. 34.5 dB C. 35 dB D. 20.5 dB
Last Answer : A. 10.5 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 : What is the primary difference between the radio horizon and the natural horizon?
Last Answer : Sea water.
Description : A man started walking from his house towards south. After walking 6 km, he turned to his left and walked 5 km after. Then he walked further 3 km after turning left. He then turned to his left and continued his walk for 9 km. How far is he away from his house? (A) 3 km (B) 4 km (C) 5 km (D) 6 km
Last Answer : Answer: C