RN 2013

RADIO NAVIGA NAVIGATION TION AND A ND COMMUNICA COM MUNICATION TION SYSTEM S YSTEM DGCA SESSION FEBRUARY 2013

www.dgcaquestionpapers.blogspot.com NOTE: All the questions are memory based so its pleasent request for all colleague to correct them if anywhere necessary. Legend: # is the answer

1) Dither motor is used to eliminate # a) laser lock b) gimbal lock c) no such motor is there

2) In this type of coupler , couplers are composed of series of lenses and partially refractive index, which coupler is this a) fused coupler # b) Beam splitting coupler c) reflection star coupler

3) In GPWS inputs take refrence from a/c configuration , radio altimeter and # a) landing gear and flaps

4) GPWS mode 1 warning # a) sink rate sink rate pull up or whoop whoop pull up

b) whoop whoop pull up and lights flashes

5) INS consists of gyroscope and accelerometer a) it will resist the a/c in level flight movement # b) it will assis t the a/c in level flight movement

6) In AM if the carrier freq is 100khz and modulating freq is 5khz, the bandwidth is a) 5khz # b) 10 khz c) 20 khz d) 100khz

7) MTCS # a) communication satellite appear to hover in given spot above the equator b) as in a and they are stationary c) satellite is not a microwave repeator repeator

8) During T/O ' Glideslope ' ' Glideslope' warning sound comes due to # a) Approaching below ILS departure b) Approaching above ILS departure

9) Satellite in close elliptical orbits require require a) low transmitting power and high receiver sensitivity b) high transmitting power and high receiver sensitivity # c) low transmitting power and low receiver sensitivity

10) LCD gate is made up of  a) TTL-XOR gate # b) CMOs - XOR gate c) DTL-XOR gate

11) If the deflection sensitivity is 0.01 mm/v and the applied voltage is 400V then the spot deflection is a) 10mm b) 400mm # c) 4mm d) 100 mm

12) VOR/ ILS aerial a) unipole aerial receiver vertical polarization # b) unipole unipole aerial mounted horizontal horizontal c) operated in 118-136 mhz d) none

13) flight management compuetr takes input from a) pitot-static tube b) ADC c) IRS/ VOR d) FMS/ INS # 1) both b and d 2) a, b and c 3) a, b, c,and d

14) cause of the duct formation in micro wave propagation # a)temp inversion b) attenuation c) reflection d) all

15) This is the push button type switch ,it is used to show or indicate whenever the electrical, hydraulic power or APU failure , the switch is a) status switch b) engine display switch c) component switch # d) event record switch

16) The maximum range in radar is determined by # a) pulse width b) beam width c) P.r.f 

17) The advantage of CW radar is a) minimum range limitation b) maximum range limitation c) range resolution # d) speed and accuracy

18) Due to ionisation of gases in ionesphere during day the effect on sky wave propagation is ..( ref: google search)

a) decrease critical angle b) skip distance increase c) dead space increase # d) all are correct

19) A 10Mhz carrier of peak value is amplitude modulated by 10 Khz singnal of  amplitude 6V the amplitude of its sideband freq is # a) 3V b) 4v c) 5v d) 6v

20 ) In F.M when freq deviation is doubled # a) the modulation is doubled b) modulatuon is halfed c) modulation remain constant d) modulation index is increased

21) In ILS Amber light illuminates for a) outer marker b) inner marker # c) middle marker d) below g/s

22) IN simple R-C filter if the capacitance value is doubled # a) cutoff freq is halfed

b) cutoff freq is double c) cutoff freq remains same d) cutoff freq becames quadrapuled

23) THe transponder reply with non altitude information a) mode B # b) mode A c) mode c d) mode D

24) when flags such as NAV , HDG, GS aare displayed in HSI the indication is a) the function is operative # b) the function is inoperative c) the system is running properly

25) In ILS system 150 hz predominate in the glideslope a) a/c is to the right of the centre line b) a/c is to the left of the centre line c) a/c is too much abovee the descent slope # d) a/c is too much below descent approach

26) for time of 900 microseconds microseconds the range would be ( hint: R= t/12.36) a) 135 NM #b) 73 NM c) 146NM d) 270 NM

27) The a/c bonding are tested for a) capacitance value b) inductance value # c) Resistance value

28) difference betwen micro processor and micro computer # a) micro procesor has small memory and micro computer has greater memory

29) In adding the a/c equipment in the cockpit increase the a/c's a) useful weight and tare weight b) empty weight and c.g shift # c) empty weight increase and useful load decrease decrease

30 ) one of the purpose of the interpole in dc generator is not to # a) reduce field strength b) reduce armature reaction c) reduce the sparking

31) The maximum no of permissable joints in a bonding at a point is a) 2 b) 3 c) 4 d) 5

32) fly by wire technology a) is te syetem where the control surface are moved mechanically b) where the data to contro the surface are moved electronically # c) the signal to control the control surface movement are transmitted transmitted elictrically through the wire

33) Hot microphone in the CVR a) can be s/w on by the pilot b) can be selected from the control panel # c) is always ON irrespective irrespective of the any selection

34) in the delta delta connection of winding # a) phase voltage = line voltage b) phase currrent = 1.73 times line current c) phase voltage is less than the line voltage

35) the coil A and b with equal crosssectional area and same number are winding are with coil A having air core and coil B with iron core then a) coil A has higher inductance inductance than B # b) ciol B has higher inductance than A

36) To avoid the radio interfnace the static discharger are discharge at a) high current b) high voltage #c ) low current d) low voltage

37 ) long range range navigation navigation sysstem determine determine a/ c location by a) measuring the inertial force acting on the a/c # b) means of te pulsed signal transmitted from the ground station c) means of sinal transmitted transmitted from the the navigation satellite satellite

38) one of the major advantge of using the a/c electrical power in the a/c is a) AC motor can be reversed while dc motor cannot be b) that the effective voltage is 1.414 times the maximum instantenious voltage # c) greater ease in step up or step down the voltage

39) In RA the wrning flags comes when the a) 26 V ac has been lost b) when the valid signal from the altimetr has been lost C) when the system doesnt work # d) when the valid signal from altimetr get lost and 26V AC failure has been occured

40) the advantage of the optical fibre used are a) it can handle less channel than the coaxial cable b) repeater can be used at distance distance of 80km c) light in weight and non- corrosive # d) both b and c

41 ) The accuracy of the area navigation is #a) directly proportional to the distance of waypoint from VORTAC station b) inv invers ersely ely propo oportio rtiona nall """" """"""

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42) what is the range of the VHF with station being at the sea level and a/c being t the height of 10000 ft a) 246 NM #b) 123 Nm c) 136 NM

43) difference between the position control and speed cotrol servo mechanism # a) tachogenartaor tachogenartaor and potentiometer b) tachometer and the potentiometer

44 ) An unweight BCD code used for error detection is a) gray code b) hexadecimal code # c) 2 by 5 code

45) the one of the following is the voltage controlled diode a) varactor diode b) tunnel diode c) esaki diode # d) zener diode

46) The main element to control the curent in the transistor is the a) emitter b) collector # c) base

47 ) when the BJT is employed as an amplifier it operates in a) saturation region b) cut-off region c) well into saturation #d) over the active region

48 ) IF amplifier is the # a) fixed frequency amplifier b) as in a and it amplifies local oscillator output

49) for the frequency stabilazaion the type of the bias used is a) collector feed back bias b) resistor bias c) rectifier bias

50 ) advantage of the double conversion a) the selectivity will be improved # b) as in a and helps to allocate more channel near same freq

51) In the resonance circuit a) f= 2 Π LC b) f= 1/ 2

 LC 

# c )  f   = 1 / 2 ∏  LC 

52) THe circuits in which the V or I changes abruptly between one value to another and continues to oscillate b/n two values it is # a) relaxation oscillator b) colpits and hartley oscillator c) colpits oscillator

53) The advantage of using the permealloy in electronics instrument is a) high speed b) accuracy c) less stray inductance

54) hetrodyniing means a) adding the RF signal with audio signal b) superimposing the two audio signal # c) mixing the modulated RF signal with unmodulated RF signal

55) In the antennae the term reciprocity means a) it will transmits from one direction and receive from another direction b) it will transmits and receive from all direction c) it will transmits and receive from one direction only d) it will transmits only

56) Capacitor with minimum loss can also be rated in terms of  a) capacitance value b) power factor c) capacitive value

d) any of above

57) in the battery a) capacity of the batery will be decreased if load is increased b) the battery being disharged at two-amp hour can be compared to the battery with unknown charged bt with same capacity c) with the decrease in the temperature the capacity of battery will deterioate

58) the coil is having 2000 turns and the current flowing through it is 5ma, calculate the amp-turn a) 20 am-turn b) 40 c) 100000 # d) 10 amp-turn

59) The battery with the 13.75 volts ssupply to the antennae the current of 0.1A ,with 6V drops in the areial unit...what is the voltage dropped at aerial unit a) 13.75 V b) 10V c) 13.60 V # d) 13.15V

60 ) The half wave rectifier provides 1414 V o/p with the diode having 25 ohm resistance in one direction and infinite ohm in other direction . the out put current is a) 15A b) 50 A c) 100.5A # d) 80.5 A

61) The motor with the actual power rating of 850 watt withdraw the current of 10 A when operted at 100 V supply then the power factor of motor will be a) 50 b) 95 # c) 85 d) 100

62) In the circuit with I and V in-phase which is true a) real power is greater greater then the apparent power b) apparent power is greater than the true power #c ) apparent power is equal to the real power

63) In the perfectly matched transmission line the VSWR wil be a) infinity b) 100 c) 0 # d) 1

64 ) The satellite data units (SDU) # a) it provides the interface unit to all other related a/c system for an aviation satellite system b) it provides the interface between the a/c station and the satellite system c) it provides the interface to the ground station and the a/c station.

65) MTCS a) quadrantal error effect the bearing indiactaion

# b)as in a and it arises from the radio frequency current circulating in the metal structurre structurre of the a/c

66) In the loop swinging a) it can be done on the ground if the a/c has loop mounted on the top of the fuselage # b) as in a and if the a/c is with the nose landing gear c) as ina and if the a/c is having the tail landing gear

67) The function of the radome is a) to protect the antennae and provide the clear antennae view b) provide the undistorted signal c) as in a with with the minimum reflection reflection of the signal signal # d) all are correct

68) The radome is protected from the errosion by a) neoperene overshoe b) neoperene coating c) polyurethrane coating # d) all are correct

69) If the electromagnetic wave have frequency of 360 Mhz this means # a) both the electric and the magnetic field are are changing at rate of 360 Mhz Mhz b) electric field is changing changing at the rate of 360 Mhz and the magnetic field field at 120 MHz c) magnetic field is altering at 360 MHz and the electric field at 120 MHz

70) Which of the following share the ommon pair of antennae a) VHF and G/S b) VOR and G/S # c) VOR and LOC

71) The stability of the carrier frequency ot the VHF system is # a) ± .005% b)+ .05% c) ± .50% d) any of above

72) In the HF system of the communication the clarifier is used which helps a) manual adjustement of the reinserted carrier frequency #b) as in a and use of the highly accurate and stable freqency synthesiser make it's provision unnecessary

73) In the SSB receiver a) carrier frequency is re-inserted b) it must have the stip skirts and nrrow bandpass within 2.5khz c) audio response is from betn 300Hz to 3000 Hz # d) all are correct

74) To speak ovver the interphone # a) the crew member should select the int. switch using the r.t, int switch in the ASP panel

75) Which of the following in the VOR system is frequency modulted a) Variable phas e signal # b) Refrence phase signal c) identification tone signal

76) MTCS in DME a) ground transponder will reply after the fixed delay of 50 microsecond b) The beacon would reply at ± 63 Mhz  rf pulse pair of the interrogation frequency c) the duration of the pulse is 3.5 microsecond # d) all are correct

77) MTCS in ATC a) the maximum interrogation rate is 480 b) in order to avoid fruiting the rate is as low as twenty to forty times a sweep c) in order to avoid fruiting the rate is inconsistent with high rate of sweep d) the pulse of the rf are .8microsec and at freq of the 1020 Mhz

78) In contrast to the parabolic reflector reflector antennae, the flat plate antene has following advantages a) higher gain b) as in a and narrower beam with low side lobe power c) as in a with increased efficiency efficiency #d) both b and c are correct

79) calculate the dopler shift if the velocity of the rf energy is C and the velocity of  a/c with V making the angle

θ 

by the beam with ground

# a)  Fd  = (2vf  cosθ ) / C  b)  Fd  = (2Vf  sin θ ) / C  c) Fd= ( 2vf  cos ecθ ) / C 

80 ) The advantage of using the high fequency in doppler rdar is that the sensitivity (Hz per knot) of radar a) remains constant #b) increase c) decrease

81) In DME and the Vortac the location of the any a/c at point is defined as the a) phantom b) phontam c) waypoint #d) both a and c are correct

82) Radio altimetr measure the heigh of the a/c a) above the sea level # b) above the ground c) no such altimeter is used

83) The radio altimeter will produce no voice a) when the a/c is on ground b) during takeoff  # c) as in b and unless negative rate of climb is detected d) as in a and unless positive rate of climb is detected

84) IF 10 ft transmission transmission line cable is used used for both VHF and the DME then then a) the loss will be increased in the DME line b) the loss will be decreased in the VHF line c) as in a and b but the antennae efficiency will not b hampered d) as in a and b but separate cable are specified by mfg for separate system

85) In order to install install the additional new radio radio equipment in the a/c a) permission is to be taknfrom the airworthines officer b) it can be done as specified in the TSO c) first the avilability of the power in the a/c should be checked d) the mfg of the a/c will permit wether it can be installed or not

86) The type of the frequency modulation used in the airport services like fire brigade , marshellr communication is a) frequency modulation b) phase moulation c) amplitude modulation d) any of above

87) SWR means a) it will be determined by the forward wave travelling in the transmission line with the reflected wave having no significance in its calculation b) the VSWR of the broad band antennae will be less as they can be operated over wide range of frequency c) IF the correct transmission line is used the VSWR will be constant without dependant on load.

88) Human speech is supposed to becomposed of different a) frequency b) phase c) amplitude #d) all above with freq betn 300Hz to 3000Hz

89) If the carrier frequency is modulated with the single tone it is called a) modulated carrier (m.w) # b) as in a and it is A2A c) as in a and it is A3A d) as in a and it is J3E

90) if the carrier frequency is modulated with human speech betn the 300Hz to 3000Hz a) two different side bands are produced b) as in case of A2A c) as in a and it is J3E #d) as in a and it is A3E

91) The gate used for the inequqlity of the low level detection is a) AND gate b) OR gate c) NOT gate d) X-OR gate

92) In electronics parallel to serial data and serial to parallel data conversion is done by

# a) data selector and data distributor distributor respectively respectively b) data distributor and data selector respectively c) in both case by data distributor only d) in both case by data selector only ( HINT: data selector is also called multiplexer and data distributor a demultiplexer)

93) when the human speech was feed to the CRO and the output was seen it was found that the output consists of the variable amplitude then at the output we use a) ? b) ? c)?

94) quest about the properties and advantage of SSB

95) quest abt modern AM transmitter a) they are low power b) they use the valve which remains open all time

**THE END** **BEST OF LUCK**