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 : 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 : 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 : 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 : What is the mixing process? A. Distortion caused by auroral propagation B. The combination of two signals to produce sum and difference frequencies. C. The elimination of noise in wideband receiver by phase differentiation D. The elimination of noise in a wideband receiver by phase comparison
Last Answer : B. The combination of two signals to produce sum and difference frequencies.
Description : What is meant by referring to electromagnetic waves as having circular polarization? A. The electric field is bent into a circular shape. B. The electric field rotates C. The electromagnetic wave continues to circle the earth D. The electromagnetic wave has been generated by a quad antenna
Last Answer : B. The electric field rotates
Description : How far away is the radio horizon of an antenna 100ft high? A. 14.14 mi B. 40km C. 14.14 km D. 40 mi
Last Answer : A. 14.14 mi
Description : Distancesnearthe skip distance should beused forthe sky-wave propagation a. to avoid tilting b.topreventsky-wave andupper rayinterference c. to avoid the Faraday effect d. so as nor to exceed the critical frequency
Last Answer : b.topreventsky-wave andupper rayinterference
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 : How to maximize the skip distance? A. Using the smallest possible radiation angle and highest possible frequency B. Using the smallest possible radiation angle and lowest possible frequency ... highest possible frequency D. Using the biggest possible radiation angle and lowest possible frequency
Last Answer : A. Using the smallest possible radiation angle and highest possible frequency
Description : Skip distance can be maximized by using the ____ radiation angle possible and the ____ frequency that will be refracted at that angle. A. lowest, lowest B. lowest, highest C. highest, lowest D. highest, highest
Last Answer : B. lowest, highest
Description : Pick out the wrong statement (A) The concentric atmosphere layer just above troposphere is called stratosphere, which is rich in ozone (B) Mesosphere is characterised by very low atmospheric ... radio waves used in the long distance radio communication are reflected back to earth by stratosphere
Last Answer : (D) The radio waves used in the long distance radio communication are reflected back to earth by stratosphere
Description : Radio fading resulting from obstruction losses. A. Log normal fading B. None of these C. Multi-path fading D. Rayleigh fading
Last Answer : A. Log normal fading
Description : Any energy which radiates in the form of radio waves, infrared waves, light waves, x-rays, etc. A. Radiant energy B. Electromagnetic C. Heat D. Ultraviolet
Last Answer : B. Electromagnetic
Description : In what year did Hertz discover radio waves? A. 1844 B. 1873 C. 1887 D. 1895
Last Answer : C. 1887
Description : The bending of radio waves passing over the top of a mountain range that disperses a weak portion of the signal behind the mountain is A. eddy-current phase effect B. knife-edge diffraction C. shadowing D. mirror refraction effect
Last Answer : B. knife-edge diffraction
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 : Skip zone is otherwise known as A. Empty zone B. Shadow zone C. Null zone D. Zone of silence
Last Answer : D. Zone of silence
Description : What is the highest frequency that can be sent straight upward and be returned to earth? A. MUF B. Gyro frequency C. Skip frequency D. Critical frequency
Last Answer : D. Critical frequency
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 : Two wires that are bent 90 degrees apart. A. Hertz B. Dipole C. Log-periodic D. Rhomic
Last Answer : B. Dipole
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 : Which region of the ionosphere is mainly responsible for long distance night time communication? A. A layer B. D layer C. E layer D. F layer
Last Answer : D. F layer
Description : Bats detect the obstacles in their path by receiving the reflected ______. a) infrasonic waves c) ultrasonic waves b) electromagnetic waves d)radio waves
Last Answer : c) ultrasonic waves
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 : RADAR means A. Radio detection and rating B. Radio detection and ranging C. Radio distance and ranging D. Radio delay and ranging
Last Answer : B. Radio detection and ranging
Description : The term ‘equinox’ means – (1) The path which the Earth takes around the Sun (2) The axis of the Earth around which it rotates (3) When the day and night are of equal duration (4) The time when the Sun seems to be going round and round in the sky in the Arctic but does not go below the horizon
Last Answer : (3) When the day and night are of equal duration Explanation: The name "equinox" is derived from the Latin aequus (equal) and nox (night), because around the equinox, the night and day have ... The term equinox can also be used in a broader sense, meaning the date when such a passage happens.
Description : The term ‘equinox’ means (1) The path which the Earth takes around the Sun (2) The axis of the Earth around which it rotates (3) When the day and night are of equal duration (4) The time when the Sun seems to be going round and round in the sky in the Arctic but does not go below the horizon
Last Answer : When the day and night are of equal duration
Description : Any small element of space in the path of a wave may be considered as a source of secondary wavelet. A. De Morgan’s Principle B. Faraday’s Law C. Huygen’s Principle D. Fresnel’s Law of optics
Last Answer : C. Huygen’s Principle
Description : what is GDOP A : Geometric dilution of position B : Geometric dilution of precisionC : Geometric dilution of path D : Geometric dilution of pointer
Last Answer : B : Geometric dilution of precision
Description : What is the process called when waves reach shallow water and are bent and tend to become parallel to the shore?
Last Answer : This is an example of refraction, as the waves are being turnedfrom their original path. This can result in the formation of alongshore (parallel) current that flows seaward as a "riptide."
Description : Light waves are bent more easily than sound waves. True or False?
Last Answer : FALSE
Description : The standard deviation of the variation in the transmission loss of a circuit should not exceed A. 3 dB B. 1 dB C. 5 dB D. 0.5dB
Last Answer : B. 1 dB
Description : ECE Board Exam March 1996 The potential difference between any exposed structured to ground in any electrical installation should not exceed _________ volts RMS. A. 10 B. 45 C. 0 D. 30
Last Answer : B. 45
Description : What is the skip zone of a radio wave?
Last Answer : A zone of silence between the ground wave and sky wave where there is no reception.
Description : The process of Deposition of Soil Materials (removed from the eluvial horizon) in the lower layer (or horizon of gains having the property of stabilizing translocated clay materials) is termed as? [a] Illuviation [b] Eluviation [c] Podsolisation [d] Mineralisation [e] None of the above
Last Answer : [d] Mineralisation
Description : Which atmospheric layer that reflects radio waves is called? -General Knowledge
Last Answer : The answer is 'Ionosphere'
Last Answer : Ionosphere Ionosphere reflects radio waves from the earth thus, helping radio communication.
Description : Which layer of the atmosphere reflects radio waves ?
Last Answer : : Radio waves are reflected from the ionic layer of the atmosphere.
Description : Which of the following types radiations is absorbed by the upper layer of the atmosphere? A. Radio-waves B. Infrared C. Visible D. Ultraviolet
Last Answer : ANSWER: B
Description : The layer of the atmosphere in which Radio Waves are reflected back is called- (1) Ionosphere (2) Troposphere (3) Stratosphere (4) Exosphere
Last Answer : (1) Ionosphere Explanation: The Radio waves are reflected back to Earth in the Ionosphere which is an electrically charged layer of the upper atmosphere. This process is used to communicate beyond the horizon, atintercontinental distances, mostly in the shortwave frequency bands.
Description : Which type of radiations are absorbed by the upper layer of the atmosphere? (1) Radio-waves (2) Infrared (3) Visible (4) Ultraviolet
Last Answer : (4) Ultraviolet Explanation: The Troposphere is the layer where the weather happens. Above this layer is the Stratosphere and in between them is the Ozone layer that absorbs the sun's ... . Above the Stratosphere is the Mesosphere, the Thermosphere including the Ionosphere - and the Exosphere.
Description : Ozone layer in the outer atmosphere helps us in – (1) reflecting radio waves and makes radio communication possible (2) regulating he temperature of atmosphere (3) absorbing cosmic ray particles (4) absorbing U-V radiations
Last Answer : (4) absorbing U-V radiations Explanation: The ozone layer is a layer in Earth's atmosphere containing relatively high concentrations of ozone (03) which absorbs 97- 99% of the Sun's medium-frequency ultraviolet light.
Description : The ozone layer protects us from - (1) Ultra violet rays (2) Radio waves (3) Visual radiation (4) Infrared radiation
Last Answer : (1) Ultra violet rays Explanation: The ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (UVR) from the sun, protecting life on Earth from its potentially harmful effects.
Description : Which layer of the earth’s atmosphere reflects back the radio waves to the earth’s surface? (1) Ionosphere (2) Stratosphere (3) Mesosphere (4) Exosphere
Last Answer : (1) Ionosphere Explanation: Long distance propagation of radio waves depends on an invisible layer of charged particles, which envelops the Earth. This layer of charged particles known as the ionosphere ... communication during the early part of the twentieth century, the ionosphere came as a boon.
Description : The atmospheric layer reflecting radio waves is called – (1) Ozonosphere (2) Ionosphere (3) Stratosphere (4) Mesosphere
Last Answer : (2) Ionosphere Explanation: The ionosphere is a part of the upper atmosphere, from about 85 km to 600 km altitude, comprising portions of the mesosphere, thermosphere and exosphere, ... importance because, among other functions, it influences radio propagation to distant places on the Earth.
Description : Which atmospheric Layer is used for the transmission of radio waves?
Last Answer : Ionosphere
Description : The layer of atmosphere which reflects radio waves is