Radio Wave Propagation MCQs

7/25/2019 Radio Wave Propagation MCQs

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1. ________ is the amount of voltage induced in wave by an electro magneticwave.

a. receive voltage

b. magnetic induction

c. eld strength

d. power density

2. An electro magnetic wave consists of ___________.

a. both electric and magnetic elds.

b. an electric eld only

c. a magnetic eld only

d. non-magnetic eld only

3. What is the lowest layer of the ionosphere

a. !1

b. !2

c. "

d. #

$. Who propounded electro magnetic radiation theory

a. %ir "dward Appleton

b. &ames 'ler( )a*well

c. 'hristian +uygens

d. %ir ,saac ewton

. /he #0 " and ! layers are (nown as ____________.

a. )ar( space ayers

b. #avinson- )iller ayers

c. ennely +eaviside ayers


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d. Appleton ayers

4. #i5erent grouping of the electromagnetic spectrum.

a. band

b. bandwidth

c. channel

d. group

6. What is the relation in degrees of the electric and magnetic elds in anelectromagnetic wave

a. 178 degrees

b. 98 degrees

c. 268 degrees

d. $ degrees

7. A changing electric eld gives rise to ________.

a. a magnetic eld

b. sound eld

c. electromagnetic waves

d. near and far elds

9. !re:uencies in the ;+! range propagate by means of

a. ground waves

b. s(y waves

c. surface waves

d. space waves

18. ,n electromagnetic waves0 polari


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c. results from the longitudinal nature of the waves

d. is always vertical in an isotropic medium

11. "lectromagnetic Waves are refracted when they ___________.

a. pass into a medium of di5erent dielectric constants

b. are polari


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c. re=ection-multipath

d. >ayleigh fading

14. /he layer that re=ects very low fre:uency waves and absorbs medium

fre:uency waves.

a. # ayer

b. " ayer

c. !1 ayer

d. !2 ayer

16. What layer is used for high-fre:uency day time propagation

a. # ayer

b. " ayer

c. !1 ayer

d. !2 ayer

17. What is the highest fre:uency that can be sent straight upward and bereturned to earth

a. );! b. s(ip fre:uency

c. critical fre:uency

d. gyro fre:uency

19. +igh fre:uency range is from

a. 8.3 to 3)+ed

b. Kellow

c. Blue

d. Ireen

68. /he :uality in sound that corresponds to color in light is

a. Amplitude

b. >esonance

c. Waveform

d. @itch

61. All real images

a. Are erect

b. 'an appear on screen

c. Are inverted


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d. 'annot appear on a screen

62. When a beam of light enters one medium from another0 a :uality thatnever changes is its

a. #irection

b. !re:uency

c. %peed

d. Wavelength

63. >elative to the angle of incidence0 the angle of refraction

a. ,s smaller

b. ,s larger

c. ,s the same

d. "ither A or B above

6$. A light ray enters one medium from another along the normal. /he angleof refraction is

a. 8

b. 98 degrees c. ":ual to the critical angle

d. #ependent on the inde*es of refraction of the two media

6. What layer aids )! surface-wave propagation a little and re=ects some+! waves in daytime

a. " layer

b. # layer

c. !1 layer

d. !2 layer

64. #ispersion is the term used to describe

a. /he splitting of white light into its component colors in refraction


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b. /he propagation of light in straight lines

c. /he bending of a beam of light when it goes from one medium toanother

d. /he bending of a beam of light when it stri(es a mirror

66. /he depth of an obCects submerged in a transparent li:uid

a. Always seems less than its actual depth

b. Always seems more than its actual depth

c. )ay seems more than its actual depth0 depending on the inde* ofrefraction of the li:uid

d. )ay seem less or more than its actual depth depending on the angleof view

67. /otal internal re=ection can occur when light passes from one medium toanother

a. /hat has a lower inde* of refraction

b. /hat has a larger inde* of refraction

c. /hat has the same inde* of refraction

d. At less than the critical angle

69. When the light ray approaches a glass-air interface from the glass side atthe critical angle0 the angle of refraction is

a. 8

b. 98 degrees

c. $ degrees

d. ":ual to the angle of incidence

78. /he brightness of light source is called its luminous intensity 0 whose unitis

a. 'andela

b. u*

c. umen


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d. !ootcandle

71. uminous eLciency is least for a

a. ow-wattage light bulb

b. )ercury vapor lamp

c. +igh-wattage light bulb

d. !luorescent tube

72. /he minimum illumination recommended for reading is

a. 7888 cd

b. 7888 l*

c. 7888 lm

d. 788 W

73. ight enters a glass plate whose inde* of refraction is 1.4 at an angle ofincidence of 38 degrees . the angle of refraction is

a. 17 degrees

b. $7 degrees

c. 19 degrees

d. 3 degrees

7$. ight leaves a slab of transparent material whose inde* of refraction is 2at an angle of refraction of 8 degrees. /he angle of incidence is

a. 8 degrees

b. $ degrees

c. 38 degrees

d. 98 degrees

7. ight enters a glass plate at an angle of incidence of $8 degrees and isrefracted at an angle refraction of 2 degrees. /he inde* refraction of theglass is


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a. 8.42

b. 1.2

c. 8.44

d. 1.4

74. An underwater swimmer shines a =ash light beam upward at an angle ofincidence of $8 degrees. /he angle of refraction is 48 degrees. /he inde* ofrefraction of water is

a. 8.46

b. 1.3

c. 8.6$

d. 1.

76. /he critical angle of incidence for light going from crown glass MnG1.N toice MnG1.3N is

a. 12 degrees

b. 8 degrees

c. $2 degrees

d. 48 degrees

77. /he solid angle subtended by a hemisphere about its center is

a. O2 sr

b. 2 O sr

c. O sr

d. depends on the radius of the hemisphere

79. the luminous =u* emitted by a 48-cd isotropic light source is

concentrated on an area of 8.m2. the illumination of the area is

a. 9.4 l*

b. 366 l*

c. 128 l*

d. 187 l*


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98. )icrowave signals propagate by way of the

a. #irect wave

b. %(y wave

c. %urface wave

d. %tanding wave

91. /he ionosphere causes radio signals to be

a. #i5used

b. Absorbed

c. >efracted

d. >e=ected

92. Iround wave communications is most e5ective in what fre:uency range

a. 388 +< to 3 )+eciprocity

384. /he fre:uency band where electromagnetic waves travel in straightpath or in a direct line of sight between the transmitter and receiver antennais

a. "!

b. +!

c. ?!

d. ?+! and above

386. /his mode of electromagnetic wave propagation uses the earthHssurface or curvature as a guide to transmit vertically polari


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d. space waves

389. the ground wave eventually disappear as it moves farther away fromthe transmitter0 because of

a. tilting

b. re=ection

c. refraction

d. di5raction

318. as electromagnetic waves travel in free space0 only one of the followingcan happen

a. absorption b. attenuation

c. refraction

d. re=ection

311. ,n polari


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a. )iller e5ect

b. @ermeability

c. 'apacitance

d. @ermitivity

31$. According to this law or principle0 a wavefront may be considered toconsist of an innite number of isotropic radiators0 each one sending outwavelets0 always away from the source.

a. %nellHs aw

b. )a*wellHs aw

c. +uygenHs @rinciple

d. Archimedes @rinciple

31. A number0 which when multiplied by the speed of light in free spacegives the speed of light in the medium in :uestion is

a. !ibonacci number

b. !ermatHs number

c. ?elocity factor

d. -factor

314. /he ability of a radio wave to be bent slightly over the edge of a sharpobstacle such as a steep hill or mountain top is

a. #i5raction

b. >e=ection

c. >efraction

d. Attenuation

316. A space wave is

a. %(y wave

b. >adio wave

c. %urface wave


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d. ine of sight propagation wave

317. ,t is a diagram indicating the intensity in voltsmeter0 in all directions0 ofthe radiated led of an antenna as it would occur under actual operatingconditions.

a. 'onstellation diagram

b. Argand diagram

c. !unicular diagram

d. >adiation pattern

319. ":uivalent to capacitance in electrical circuits

a. ,nductance b. @ermittivity

c. @ermeability

d. @ower density

328. All of these cause attenuation e*cept

a. /ilting

b. Iround absorption c. Atmospheric absorption

d. %urface wave propagation

321. /he transmission of radio waves far beyond line of sight distances byusing high power and large transmitting antennas to beam the signal upwardinto the atmosphere and a similar large receiving antenna to pic( up a smallportion of the signal scattered by the atmosphere is called

a. !orward scatter propagation b. Beyond the hori


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322. /he apparent height of an ioni


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324. /he process by which a radio wave is bent and returned to earth fromone medium to another after stri(ing them is

a. >e=ection

b. >efraction c. #i5raction

d. Absorption

326. An incident0 traveling obli:uely from one medium to another0 willundergo a change in direction if the velocity of the wave in one medium isdi5erent from that in the other and the ratio of the sine of the angle ofincidence to the sine of the angle of refraction is the same ratio ofrespectively wave velocities in these media. /his law is called

a. %nellHs aw

b. !isherHs aw

c. +oo(eHs aw

d. ewtonHs aw

327. /he lowest layer of the ionosphere which e*ists between 8 to 98 (mfrom the earthHs surface and re=ects ?! and ! waves while absorbing )!and +! waves during daytime is the

a. # layer

b. " layer

c. ! layer

d. ?antress layer

329. /his phenomenon occurs when the thic(er air is on top instead of beingat the bottom when the temperature of water vapor gradient is lesser orgreater than the standard rate.

a. /hermal inversion

b. +ori


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338. An ionospheric layer0 which e*ists between 98 to 128 (m above theearthHs surface and is about 2 (m thic(. ,t aids )! surface propagationwhile re=ecting some +! during daytime

a. #-layer

b. "-layer

c. ! layer

d. ?antress layer

331. Atmospheric condition is controlled by

a. @ressure

b. /emperature

c. +umidity

d. All of these

332. /his ionospheric layer forms at night at about 388 (m from the earthHssurface and is responsible for long distance +! wave propagation due tore=ection and refraction. ,t splits during daytime due to the ioni


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33$. @ower density is inversely proportional to the s:uare of the distancefrom the source or transmitter to the destination or receiver. /his law iscalledR

a. 'oulombHs law

b. aw of ;niversal Iravitation

c. ,nverse %:uare aw

d. en


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337. /he transfer of electromagnetic waves or acoustical energy from oneplace to another through a suitable transmission medium is

a. Wave propagation

b. >! induction c. >adio !re:uency ,nterference

d. !orward %catter

339. /he upper limit of fre:uencies that can be used at a specied time forradio transmission between two points and involving propagation byre=ection from regular ioni


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b. /he transmitting antennas are of convenient sie=ected by the # layer

c. 'apable of use for long-distance communications on the moon

d. A5ected by the solar cycle

3$$. #istances near the s(ip distance should be used for s(y-wave

propagation

a. /o avoid tilting

b. /o prevent s(y-wave and upper ray interference

c. /o avoid the faraday e5ect

d. %o as not to e*ceed the critical fre:uency

3$. /he ground wave eventually disappears0 as one moves away from thetransmitter0 because of

a. ,nterference from the s(y wave

b. oss of line of sight conditions

c. )a*imum single-hop distance limitation

d. /ilting

3$4. ,n electromagnetic waves0 polariesults from the longitudinal nature of the waves

d. ,s always vertical in an isotropic medium

3$6. >adio fading resulting from obstruction losses.


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a. og normal fading

b. >ayleigh !ading

c. )ulti-path fading

d. one of these

3$7. /he absorption of radio waves by the atmosphere depends on

a. /heir fre:uency

b. /heir distance from the transmitter

c. /he polari! propagation

b. >adio propagation

c. Wave propagation

d. All of these


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32. "lectromagnetic waves are

a. 'onsist of electric and magnetic component that are parallel to eachother

b. Fscillations that propagate through free space c. ,rregular oscillations

d. Fscillations that are produced by an oscillating circuit

33. /he region around an electrically charged body in which other chargedbodies are acted by an attracting or repelling force.

a. "lectric eld

b. >adiation eld

c. )agnetic eld

d. "lectromagnetic eld

3$. What are the two components of electromagnetic eld

a. >ay and wavefront

b. )agnet and electricity

c. @olar electrons and magnetic eld

d. "lectric eld M"-eldN and magnetic eld

3. %hows a surface of constant phase of a wave and is formed when pointsof e:ual phase on rays propagated from the source are Coined together.

a. >ay

b. Wavefront

c. @oint source

d. ,sotropic source

34. ,t is a line drawn along the direction of propagation of anelectromagnetic wave used to show the relative direction of electromagneticwave propagation.

a. >ay


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b. Wavefront

c. @oint source

d. ,sotropic source

36. >efers to the rate at which energy passes through a given surface areain free space

a. !ield intensity

b. @ower density

c. >efractive inde*

d. Absorption coeLcient

37. ,t itHs the intensity of the electric and magnetic elds of anelectromagnetic wave propagating in free space

a. !ield intensity

b. @ower density

c. >efractive inde*

d. Absorption coeLcient

39. ,n a lossless transmission medium0 _______ of free space is e:ual to the

s:uare root of the ratio of its magnetic permeability to its electric permittivity

a. >esistance

b. !ield intensity

c. 'haracteristic impedance

d. A or ' is correct

348. "lectromagnetic wave measures all e*cept

a. ,nductance

b. @ower density

c. )agnetic eld intensity

d. @ermittivity of the medium


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341. A reduction in power density due to the inverse s:uare law presumesfree-space propagation is called

a. Absorption

b. Wave attenuation c. %pace attenuation of the wave

d. B or ' is correct

342. Which of the following are optical e5ects of radio waves

a. >efraction and re=ection

b. #i5raction and interference

c. ,nduction and di5raction d. A and B

343. What is di5raction

a. ,s the change in direction of a ray as it passes obli:uely from onemedium to another with di5erent velocities or propagation

b. >efers to the modulation or redistribution of energy within awavefront when it passes near the edge of an opa:ue obCect

c. ,s the phenomenon that allows light or radio waves to travel Mpee(Naround corners of an obstacle.

d. A or ' is right

34$. A rare refracting medium has

a. %maller value of dielectric constant

b. +igher value of dielectric constant

c. ?ariable value for dielectric constant

d. A dielectric constant dependent on the medium

34. >efractive inde* refers to

a. /he ratio of velocity of light in free space to the velocity of light in agiven material


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36$. Any space or region wherein a magnetic force is e*erted on movingelectric charges

a. "lectric eld

b. >adiation eld c. )agnetic eld

d. "lectromagnetic eld

36. Which of the following is a characteristic of electromagnetic wave

a. )easures power0 voltage0 capacitance and impedance of a system

b. )easures power density0 voltage0 and inductance

c. )easures power density0 magnetic eld intensity0 and electric eldintensity

d. All of the above

364. >e=ection waves

a. %hould ta(e place at one medium

b. #oes not necessarily ta(e place at one medium

c. Fccurs at any other medium at the same time

d. ,s not possible

366. WayMsN of propagating electromagnetic wavesR

a. Iround-wave propagation

b. %pace wave propagation

c. %(y-wave propagation

d. All of these

367. At fre:uencies below 1. )+


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c. %(y wave

d. All of these

369. Which of these causes the wavefront to tilt progressively forward

a. Iradient density

b. "lectric eld intensity

c. Absorption coeLcient

d. )agnetic eld intensity

378. Which of following of must be ta(en into consideration to ensure properground-wave propagation

a. @ower

b. /errain

c. !re:uency

d. B and '

371. What are the applications of groundwave propagation

a. %hip-to-ship and ship-to-shore communications

b. )aritime mobile communications

c. >adio navigation

d. All of these

372. /he curvature of the earth presents a hori


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a. 'hanges in troposphereHs density and temperature

b. Water vapor content

c. >elative conductivity

d. All of the above

37$. Any of the =owing can be caused to lengthen radio hori


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d. ! layer

392. /he apparent height of the ioni


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394. 'oncerns to the single re=ection of a radio wave form the ionospherebac( to earth.

a. &og

b. +op c. %(ip

d. !ading

396. /he =uctuation of signal strength at the receiver that are caused bychanges in the transmission medium

a. !ading

b. +opping

c. %(ipping

d. #iversity

397. Iradual variation in the eld strength of a radio signal is compensatedby

a. !ading techni:ues

b. #iversity techni:ues

c. /ransverse techni:ues

d. /ransmission techni:ues

399. A modulation of two di5erent >! carrier fre:uencies with the same ,!intelligence0 then transmitting both >! signals to a given destination.

a. #iversity

b. %pace diversity

c. !re:uency diversity

d. @olari


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a. %pace diversity

b. !re:uency diversity

c. @olari

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Radio Wave Propagation MCQs

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