Description : Indicatewhich one ofthe followingreasonsforthe use of a groundscreenwith antennasisfalse: a. Impossibility of a good ground connection b. Provision of an earth for the antenna c.Protectionofpersonnelworkingunderneath d. Improvement of the radiation pattern of the antenna
Last Answer : c.Protectionofpersonnelworkingunderneath
Description : Indicatewhich ofthe followingreasonsfor usinga counterpoisewith antenna isfalse: a. Impossibility of a good ground connection b.Protectionofpersonnelworkingunderground c. Provision of an earth for the antenna d. Rockiness of the ground
Last Answer : b.Protectionofpersonnelworkingunderground
Description : Indicatewhich ofthe followingfrequencies cannotbe used forreliablebeyond-the-horizon terrestrial communicationswithoutrepeaters: a. 20 kHz b. 15 MHz c. 900 MHz d. 12GHz
Last Answer : d. 12GHz
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 : Whichofthe followingterms describesthe reason thatlightisrefractedat different angles? a. Photon energy changes with wavelength b. Light is refracted as a function of surface smoothness c. The angle is determined partly by a and b d. The angle is determined by the index of the materials
Last Answer : d. The angle is determined by the index of the materials
Description : Whichoneofthe followingterms doesnot applyto theYagi-Uda array? a. Good bandwidth b. Parasitic elements c. Folded dipole d.Highgain
Last Answer : d.Highgain
Description : What propagation condition is usually indicated when a VHF signal is received from a station over 500 miles away? A. D-layer absorption B. Faraday rotation C. Tropospheric ducting D. Moonbounce
Last Answer : C. Tropospheric ducting
Description : What propagation condition is usually indicated when a VHF signal is received from a station over 5000 miles away? A. Moonbounce B. D-layer absorption C. Tropospheric ducting D. Faraday rotation
Description : Which ofthe followingcableswill have the highestlaunch power capability? a. 50/125/0.2 b. 85/125/0.275 c. 62.5/125/0.275 d. 100/140/0.3
Last Answer : d. 100/140/0.3
Description : One ofthe followingis not a reason forthe use of anantenna coupler: a. To make the antenna look resistive b. To provide the output amplifier with the correct load impedance c. To discriminate against harmonics d. To prevent reradiation of the local oscillator
Last Answer : d. To prevent reradiation of the local oscillator
Description : One ofthe followingis veryuseful as amultibandHFreceivingantenna.Thisisthe: a. conical horn b. folded dipole c. log periodic d. square loop
Last Answer : c. log periodic
Description : One ofthe followingconsistsof nonresonant antennas: a.The rhombic antenna b. The folded dipole c. The end-fire array d. The broadside array
Last Answer : a.The rhombic antenna
Description : Themaindisadvantage ofthe two-hole directional coupleris a. low directional coupling b. poor directivity c. high SWR d.narrowbandwidth
Last Answer : d.narrowbandwidth
Description : Whenmicrowave signalsfollowthe curvatureofthe earth,thisisknownas a. the Faraday effect b.ducting c. tropospheric scatter d. ionospheric reflection
Last Answer : b.ducting
Description : The phenomena of induced emf was observed by Faraday and Henry in: a. 1931 b. 1831 c. 1535 d. 1940
Last Answer : a. 1931
Description : Electric current produces magnetic field was suggested by: a. Faraday b. Lenz c. Ohm d. Oerested
Last Answer : c. Ohm
Description : The concept of electric field theory was introduced by: (a) Kepler (b) Newton (c) Dalton (d) Michael Faraday
Last Answer : (d) Michael Faraday
Description : Michael Faraday was known by his work on: (a) Electric force (b) Weak nuclear force (c) Strong nuclear force (d) Gravitational force
Last Answer : (a) Electric force
Description : Compare sky wave and space wave propagation w.r.t. following points. (i) Frequency range (ii) Effect of fading (iii)Polarization (iv)Application
Last Answer : Sr. No Parameters Sky Wave Propagation Space Wave Propagation 1 Frequency range 3 MHz to 30 MHz Above 30 MHz 2 Effect of fading Problem of fading is ... horizontally Polarized 4 Application RadioBroadcasting (SW Range) Used for TV and FM broadcasting
Description : Define fading w.r.t. wave propagation.
Last Answer : Fading: The fluctuation in signal strength at a receiver, which is mainly due to the interference of two waves which left the same source but arrived at the destination by different paths, is known as fading.
Description : Thehigherthe index number a. the higher the speed of light b. the lower the speed of light c. has no effect on the speed of light d. the shorter the wavelength propagation
Last Answer : a. the higher the speed of light
Description : Electromagneticwaves are refractedwhen they a. pass into a medium of different dielectric constant b. are polarized at right angles to the direction of propagation c. encounter a perfectly conducting plane d. pass through a small slot in a conducting plane
Last Answer : a. pass into a medium of different dielectric constant
Description : Which one of the following waves requires a material medium for their propagation? a) Light waves b) X– rays c) -rays d) Sound waves
Last Answer : d) Sound waves
Description : The propagation of the electromagnetic waves can be illustrated by a) Faraday law b) Ampere law c) Flemming rule d) Coulomb law
Last Answer : c) Flemming rule
Description : How can the direction of rotation of an AC motor be reversed?*
Last Answer : By interchanging any two supply lines.
Description : How does this cause a rotation to change?
Last Answer : Due to the change in phase sequence, the rotating magnetic field changes direction and the rotor rotates in the opposite direction.
Description : How is the direction of rotation varied?
Last Answer : By changing the phase sequence (from say R-Y-B to R-B-Y)
Description : Moist atmospheric air at high temperature (e.g., in summer) having high concentration of sulphur dioxide causes (A) Fading of dyes on textiles (B) Corrosion, tarnishing & soiling of metals (C) Reduced strength of textiles (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Presence of high concentration of ozone and smog in atmospheric air causes the (A) Embrittlement & decrease of folding resistance of paper (B) Cracking of rubber products (C) Fading of dye on textiles (D) Damage of electrical insulator on high tension power line
Last Answer : (B) Cracking of rubber products
Description : What antenna can be used to minimize the effect of Faraday rotation of polarization? A. Dipole B. Parabolic C. Helical D. Rhombic
Last Answer : C. Helical
Description : In order to obtain spectrum from the emitted radiation, the atomic gas or vapour must be excited at a) much less than atmospheric pressure b) much high than atmospheric pressure c) atmospheric pressure d) high pressure and temperature
Last Answer : a) much less than atmospheric pressure
Description : What is the full form of 'SIDS' ? -How To ?
Last Answer : The full form of 'SIDS' is Sudden Infant Death Syndrome
Last Answer : SIDS - Sudden Infant Death Syndrome
Last Answer : Sudden Infant Death Syndrome , the full form of SIDS
Description : The perimeter of a polygon is the ttal length of its sides. In a regular polygon of n sids with x as the length of a side, the perimeter P is________
Last Answer : The perimeter of a polygon is the ttal length of its sides. In a regular polygon of n sids with x as the length of a side, the perimeter P is________
Description : What is Sid's physical appearance?
Last Answer : Feel Free to Answer
Description : Who is sids family?
Last Answer : SIDS FAMILY ASSOCIATION Japan WAS FOUNDED IN 1993 TO HELP FAMILIES WHO HAVE SUFFERED LOSSING A BABY FOR ANY REASON INCLUDING MISSCARRIAGE,STILLBIRTH,PERINATAL DEATH, OR INFANT DEATH
Description : How to Prevent SIDS ?
Last Answer : How to Prevent SIDS Sudden Infant Death Syndrome (SIDS) occurs when an infant unexpectedly dies without any cause. There have been numerous research done to find out its cause. There are still no ... pregnancy, take care of your baby properly and check on him frequently even when he's asleep.
Description : Atmospheric pressure exerted on the earth is due to the _____ A. Rotation of the Earch B. Revolution of the earth C. Grasvitational pull D. Uneven heating of the earth
Last Answer : ANSWER: C
Description : Atmospheric pressure exerted on earth is due to : (1) rotation of earth (2) revolution of earth (3) gravitational pull (4) uneven heating of earth
Last Answer : (3) gravitational pull Explanation: The atmosphere is made up of gasses. Gasses are physical substances, and all physical substance has weight. The atmosphere is 25 miles thick, and that 25 miles ... square inch because of the gravitational pull. That's how atmosphere exerts pressure on the earth.
Description : The atmospheric air is held to the Earth by – (1) gravity (2) winds (3) clouds (4) rotation of the Earth
Last Answer : (1) gravity Explanation: The atmosphere is an ocean of air held in place by gravity, extending from the surface to an altitude of hundreds of kilometers, the edge of space. Energy from the sun heating the air and land surface to different degrees, drives atmospheric circulation.
Description : The atmospheric air is held to the Earth by : (1) gravity (2) winds (3) clouds (4) rotation of the Earth
Last Answer : gravity
Last Answer : gravitational pull
Description : By changing the dimensions of the viewport, the and ofthe objects being displayed can be manipulated. a.Number of pixels and image quality b.X co-ordinate and Y co-ordinate c.Size and proportions d.All of these
Last Answer : c.Size and proportions
Description : Which one ofthe following describes the lithosphere? -Geography
Last Answer : (b) Crust and upper mantle
Description : The letters ofthe word ‘NATIONAL’are arranged atrandom. What is the probability that the last letter will be T ? -Maths 9th
Last Answer : (c) \(rac{1}{8}\)Let S be the sample space.Then n(S) = Total number of ways in which the letters of word NATIONAL can be arranged= \(rac{8!}{2!\,2!}\) (∵There are 2A s and 2N's in 8 letters)Let E : Event of ... !}{2!\,2!}}\) = \(rac{7!}{8!}\) = \(rac{7!}{8 imes7!}\) = \(rac{1}{8}\).
Description : Did Mary Shelley wife ofthe poet write dracula or franconstin?
Last Answer : What is the answer ?
Description : In the ring topology what happens if one ofthe stations is unplugged?
Last Answer : Need answer
Description : Rights of Minorities, including their due representation in the government, are provided in Article _________ ofthe Constitution. A. 35 B. 36 C. Both 35 and 36 D. None of these 99
Last Answer : ANSWER: B
Description : acode is simply a subset of the vertices ofthe a. n bit b. ncube c. n single d. n double
Last Answer : b. ncube