Description : Cassegrain feedis usedwith a parabolic reflectorto a. increase the gain of the system b. increase the beamwidth of the system c. reduce the size of the main reflector d. allowthe feedtobeplacedata convenientpoint
Last Answer : d. allowthe feedtobeplacedata convenientpoint
Description : A dipole antenna requires to be fed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11kW ... Gain referred to this particular dipole). A. 4.75 B. 2.6 C. 1.81 D. 4.24
Last Answer : B. 2.6
Description : _____ is an open-ended slot antenna A. Helical antenna B. Rhombic antenna C. Notch antenna D. Cassegrain antenna
Last Answer : C. Notch antenna
Description : Earth station uses what type of antenna A. Despun antenna B. Helical antenna C. Toroidal antenna D. Cassegrain antenna
Last Answer : D. Cassegrain antenna
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 : Which of the following improves antenna directivity? A. Driven element B. Reflector element C. Director element D. Parasitic element
Last Answer : D. Parasitic element
Description : Known as the technique for adding a series inductor at or near the center of an antenna element in order to cancel the capacitive reactance of an antenna. A. Dipole B. Center loading C. Reflector D. loading coil
Last Answer : D. loading coil
Description : The reflector and director of an antenna array are considered as A. Parasitic elements B. Transcendental elements C. Feed-points D. Driven elements
Last Answer : A. Parasitic elements
Description : A dipole antenna requires to be feed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11 ... ( Gain referred to this particular dipole) A. 4.24 B. 1.81 C. 4.75 D. 2.6
Last Answer : D. 2.6
Description : A type of array antenna which consists of one half-wave driven dipole, one reflector and one director A. Hertzian dipole B. Yagi-uda C. Broadside collinear D. Log periodic dipole array
Last Answer : B. Yagi-uda
Description : ECE Board Exam March 1996 An antenna that is circularly polarized is the ____________. A. parabolic reflector B. helical C. Yagi-uda D. small circular loop
Last Answer : B. helical
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 : Which antenna radiates an omnidirectional pattern in the horizontal plane with vertical polarization? A. Marconi antenna B. Discone antenna C. Horn antenna D. Helical antenna
Last Answer : A. Marconi antenna
Description : _________ detects the satellite signal relayed from the feed and converts it to an electric current, amplifies and lower its frequency. A. Horn antenna B. LNA C. Satellite receiver D. Satellite dish
Last Answer : B. LNA
Description : A special horn antenna consisting of a parabolic cylinder joined to a pyramidal horn. A. Hoghorn B. Cass-horn C. Pyramidal horn D. Conical horn
Last Answer : A. Hoghorn
Description : A parabolic dish antenna isa(n)_______ antenna. A) omnidirectional B) bidirectional C) unidirectional D) horn
Last Answer : unidirectiona
Description : The most widely used antenna in GPS is (A) Parabolic antenna (B) Microstrip antenna (C) Horn antenna (D) Slotted antenna
Last Answer : Answer: Option B
Description : Zoningis usedwith adielectric antenna inorderto a. reduce the bulk of the lense b. increase the bandwidth of the lens c. increase pin-point focusing d. correct the curvature of the wavefront from a horn that is too short
Last Answer : a. reduce the bulk of the lense
Description : Draw the structure and state applications of: i) Ferrite loop (rod) antenna ii) Horn antenna
Last Answer : Horn antenna: Application:- i) Used at microwave frequency. ii) Used in satellite tracking. Ferrite loop antenna: Application:- In Am radio receiver to receive MW and SW band signals. In FM radio receiver
Description : Write one application of following antenna i. Rectangular antenna ii. Dish antenna iii. Yagi-Uda antenna iv. Horn antenna
Last Answer : i. Rectangular antenna is used in direction finding in portable recievers. ii. Dish antenna is used to transmit and receive signal from satellite. iii. Yagi-Uda antenna is used in HF and VHF range as a TV receiving antenna. iv. Horn antenna is used in satellite tracking.
Description : Draw radiation pattern for following antenna i) Yagi-Uda antenna ii) Loop antenna iii) Dish antenna iv) Horn antenna
Last Answer : Type of antenna Radiation Patteren Yagi-Uda antenna Loop antenna Dish antenna Horn antenna
Description : Draw the structure of horn antenna and its radiation pattern. List its any two applications.
Last Answer : The structure of horn antenna Radiation pattern of Horn Antenna Application:- i) Used at microwave frequency. ii) Used in satellite tracking
Description : Write the application of the following antennas: 1) Rectangular antenna 2) Dish antenna 3) Horn antenna 4) Loop antenna 5) Yagi-Uda antenna.
Last Answer : Applications: 1.Rectangular antenna i)Used in Mobile and satellite communication ii)Used in Global Positioning System iii) Used for Radio Frequency Identification (RFID) iv) Radar Dish ... antenna. 2. Yagi-Uda antenna is used in conditional Access System (CAS) at the decryptor.
Description : Increasing the resonant frequency of an end-fed Marconi antenna can be done by A. adding a capacitor in series and reducing the physical length B. adding an inductor in series C. adding an inductor in series D. All of these
Last Answer : A. adding a capacitor in series and reducing the physical length
Description : A shunt-fed quarter-wavelength Marconi antenna A. has maximum RF impedance to ground at its feedpoint B. has a current null at its feedpoint C. has a zero DC resistance to ground D. has zero RF resistance to ground
Last Answer : C. has a zero DC resistance to ground
Description : A one-quarter wavelength shunt-fed vertical Marconi antenna A. has maximum radiation in a vertical direction B. must have a horizontal receiving antenna for the best reception C. must use a receiving antenna for the best reception D. must have a vertical receiving antenna for the best reception
Last Answer : D. must have a vertical receiving antenna for the best reception
Description : The power fed to a two-bay turnstile antenna is 100 watts. If the antenna has a 2 dB power gain, what is the effective radiated power? A. 317 watts B. 158 watts C. 200 watts D. 400 watts
Last Answer : B. 158 watts
Description : If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter? A. 70 watts B. 50 watts C. 25 watts D. 6 watts
Last Answer : D. 6 watts
Description : What is a driven element of an antenna? A. Always the rearmost element B. Always the forwardmost element C. The element fed by the transmission line D. The element connected to the rotator
Last Answer : C. The element fed by the transmission line
Description : What is the gain of four identically polarized antennas stacked one above the other and fed in phase? A. 3 dB over the gain of one antenna B. 10 dB over the gain of one antenna C. 4 dB over the gain of one antenna D. 6 dB over the gain of one antenna
Last Answer : D. 6 dB over the gain of one antenna
Description : It consists of a number of dipoles of equal size, equally spaced along a straight line with all dipoles fed in the same phase from the same source. A. Log-periodic antenna B. Yagi antenna C. End-fire array D. Broadside array
Last Answer : D. Broadside array
Description : It is the same with directive gain except that the total power fed to the antenna is used and the antenna efficiency is taken into account.
Last Answer : power gain
Description : To hear a clear resonance, what must be the distance between the listener and the reflector? -General Knowledge
Last Answer : answer:
Description : What is the degree of angle between the perpendicular and the reflector ?
Last Answer : The angle between the perpendicular and the reflector is 90 degrees.
Description : Who Invented the Reflector Telescope ?
Last Answer : Scientist Newton invented the reflecting telescope.
Description : What is the minimum distance between the reflector and the source to hear the echo? ?
Last Answer : The minimum distance between the reflector and the source to hear the echo is 18.6 meters.
Description : What is the difference between reflex and reflector telescope ?
Last Answer : refractive telescope 1. This device uses two or three convex lenses or one convex lens and one concave lens to form reflection through refraction. 2. The color of the reflection in this device is ... 5. It is relatively easy to make mirrors for large children. . The scattering capacity is high.
Description : What is the midpoint of the reflector surface of a spherical mirror called ?
Last Answer : The center point of the reflecting surface of a spherical mirror is called pole.
Last Answer : The medium through which the word is reflected back is called the reflector.
Description : To hear a clear echo, the distance between the listener and the reflector should be
Last Answer : 17 METER
Description : A white and smooth surface is – (1) good absorber and good reflector of heat (2) bad absorber and good reflector of heat (3) good absorber and bad reflector of heat (4) bad absorber and bad reflector of heat
Last Answer : (2) bad absorber and good reflector of heat Explanation: Shiny surfaces are poor absorbers of heat radiation and the best reflectors of heat radiation. Black surfaces are the best emitters and best absorber of heat radiation.
Description : The earth is a – (1) good reflector of heat (2) non-absorber of heat (3) good absorber and good radiator of heat (4) bad absorber and bad radiator of heat
Last Answer : (3) good absorber and good radiator of heat Explanation: The earth's surface radiates as a black body, since it aborts and radiates with nearly 100 percent efficiency for its temperatures. Gases, on the contrary, are selective absorbers and radiators.
Description : Convex mirror is generally used in - (1) solar cookers (2) opthalmoscope (3) reflector for head light (4) rear view mirror
Last Answer : (4) rear view mirror Explanation: Rear view mirrors of carsare convex mirrors as they enable the driver to see a wide area of the road behind the car. The convex mirror makes the rays of ... if they were coming from its focus, thereby produdcing a diminished virtual image which the driver can see.
Description : Which nuclear reactor uses water as a coolant, moderator and reflector ?
Last Answer : Pressurised water reactor.
Description : The main function of a communications satellite is a/ an A. repeater B. reflector C. beacon D. observation platform
Last Answer : A. repeater
Description : Which of the following is the basic component of a communications satellite receiver? A. On-board computer B. Reflector C. Telemetry D. Transponder
Last Answer : D. Transponder
Description : A concave mirror cannot be used as : (a) a magnifying mirror (b) a torch reflector (c) a dentist‘s mirror (d) a rear view mirror
Last Answer : (c) a dentist‘s mirror
Description : A perfect conductor acts as a a) Perfect transmitter b) Perfect reflector c) Bad transmitter d) Bad reflector
Last Answer : b) Perfect reflector
Description : A perfect dielectric acts as a a) Perfect transmitter b) Perfect reflector c) Bad transmitter d) Bad reflector
Last Answer : a) Perfect transmitter
Description : The broadside array consists of a flat reflector and what other elements?
Last Answer : Two or more half-wave dipoles.