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Badly Phrased, Contradictory, Doubtful or Wrong Questions

 
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K.Haroon
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PostPosted: Thu Jan 31, 2013 10:45 pm    Post subject: Badly Phrased, Contradictory, Doubtful or Wrong Questions Reply with quote

Arrow Ground DME responders respond at a frequency:

a) the same as the interrogation signal
b) 63 MHz greater than interrogation frequency
c) 63 MHz lower than interrogation frequency
d) 63 MHz different from interrogation frequency, either above or below

b) marked correct whereas (d) seems to be correct. (for exam id, there seems to be no other similar to this)


Arrow At a height of 5,000 feet you might expect to receive a VHF signal, from a transmitter at sea level, at a range of:

a) 88,4 nm
b) 88,4 nm
c) 70,7 nm
d) 200 km

a) correct but both a) and b) are same.


Arrow An aircraft, on a heading of 180oM is on a bearing of 270oM from a VOR. The bearing you should select on the OMNI bearing selector to centralise the VOR/ILS left/right deviation needle is:

a) 360
b) 270
c) 090
d) 180

c) marked correct whereas both (c) and (b) can be correct. This was appealed and the UK CAA agreed there was an error and say they have modifed the question to make the given answer the only correct one. So we need to see the correct question. (for exam id, there seems to be no other similar to this)


Arrow If you correctly tuned in a VOR situated to your east, your RMI should read ___ and your OBS would read ___

a) 000; 000 with needle central and TO indicated
b) 090; 090 with needle central and FROM indicated
c) 000; 000 with needle central and FROM indicated
d) 090; 090 with needle central and TO indicated

c) marked correct whereas (d) seems to be correct. (for exam id, there seems to be no other similar to this).


Arrow An aircraft carrying out a 3o glidepath ILS approach experiences a reduction in ground speed from 150 kt at the outer marker to 120 kt over the threshold. The effect of this change in ground speed on the aircrafts rate of descent will be a decrease of approximately:

a) 150 FT/MIN
b) 250 FT/MIN
c) 50 FT/MIN
d) 100 FT/MIN

c) marked correct whereas (a) is correct (for exam id, the unique part is FT/MIN)

On a 3 degree Glide Path.

Rate of Descent = Ground Speed x 5

AT 150 kts (150 x 5) = 750

AT 120 kts (120 x 5) = 600

The difference is 150 not 50

On Glide Paths other than 3 degrees:

Rate of Descent = Ground Speed x 5 x (Glide Path/3)

Another similar question marked correctly is:

An aircraft on a 3o ILS approach is flying a ground speed of 150 knots. At the outer marker (4.5 nm from the threshold) the speed must be reduced to 120 knots. The ROD should be reduced by:

a) 120 fpm
b) 150 fpm
c) 170 fpm
d) 190 fpm

b) correct and marked correct.


Arrow On what carrier frequency does the inner marker transmit?

a) Same frequency as the localiser
b) 75 MHz
c) Same frequency as the glide path
d) 3000 Hz

d) marked correct whereas (b) is correct. (for exam id, there seems to be no other similar to this)

All ILS marker beacons transmit on the same carrier wave frequency of 75Mhz. The amplitude modulation superimposed on that carrier that is different for the three markers. Outer marker 400Hz AM, Middle marker 1300Hz AM, Inner marker 3000Hz AM.


Arrow For reliable navigation information the approximate coverage of a 3o ILS glide slope is:

a) 0.7o above and below the glide path and 8o either side of the localiser centre line
b) 0.45o from the horizontal to 1.75o above the glide path and 8o either side of the localiser centre line
c) 1.5o to 5o from the horizontal and 8o either side of the localiser
d) 3o above and below the glide path and 10o either side of the localiser centre line

c) marked correct whereas (b) is correct.

Identification of the incorrectly marked question (if it comes in the exam) is the appearance of the phrase "For reliable navigation information the approximate coverage.."


Arrow PAR at a military airfield has both azimuth and an elevation element. It must be able to provide an accuracy within:

a) 30 feet elevation, 20 feet azimuth
b) 30 feet azimuth, 20 feet elevation
c) 30 feet elevation and azimuth
d) 20 feet elevation and azimuth

a) marked correct whereas b) is correct.

Ref: PAK CAA / RADIO NAVIGATIONAL AIDS / AIR NAVIGATION ORDER / PAR Accuracy / Page 43,44 [http://www.caapakistan.com.pk/downloads/ANO-002-DRTS-1.0.pdf]


Arrow With the AWR set at 100 nm range a large cloud appears at 50 nm. If the range is reduced to 50 nm:

a) The image will decrease in area and remain where it is
b) The image will decrease in area and move to the top of the screen
c) The image will increase in area and move to the bottom of the screen
d) The image will increase in area and move to the top of the screen

b) marked correct whereas (d) seems correct. Identification of the incorrectly marked question (if it comes in the exam) is the appearance of the phrase "AWR set at 100 nm".

Other similar questions are:

1) A weather radar, set to the 100 NM scale, shows a squall at 50 NM. By changing the scale to 50 NM, the return on the radar screen should:

a) decrease in area and move to the top of the screen
b) increase in area and appear nearer to the bottom of the screen
c) decrease in area but not change in position on the screen
d) increase in area and move to the top of the screen <-- Marked Correct


Arrow A secondary radar can provide up to 4096 different codes. These 4096 codes can be used in:

a) mode C only
b) mode A only
c) all modes
d) mode S

d) marked correct whereas (c) seems correct. Identification of the incorrectly marked question (if it comes in the exam) is the appearance of "4096" twice in the question.

Other similar questions are:

1) The availability of 4096 codes in SSR is applicable to mode:

a) A
b) C
c) S
d) All <-- Marked Correct


Arrow In order to indicate radio failure the aircraft SSR transponder should be selected to code:

a) 7000
b) 7700
c) 7600
d) 7500

d) marked correct, whereas (c) is correct. Identification of the incorrectly marked question (if it comes in the exam) is that all four answer choices are in digits in the decreasing order 7700, 7600, 7500.

Other similar questions are:

1) What transponder code is selected in the event of radio failure:

a) 7000
b) 7500
c) 7600 <-- Marked Correct
d) 7700

2) The selection of code 7600 on an aircraft SSR transponder indicates:

a) an emergency
b) unlawful interference with the planned operation of the flight
c) transponder malfunction
d) radio communication failure <-- Marked Correct

3) In special Condition signals, to signify radio failure, which of the following codes should you select on your transponder?

a) 7700
b) ident
c) 7500
d) 7600 <-- Marked Correct

4) The SSR code for a total radio failure is:

a) A7500
b) A7600 <-- Marked Correct
c) A7500 plus mode C
d) A7600 plus mode C


Arrow SSR is not affected by weather clutter because:

a) It uses different frequencies for transmission and reception
b) The wavelength is too short to be reflected from cloud droplets
c) The equipment uses a moving target indicator
d) The frequency used penetrates clouds

d) marked correct whereas (a) is correct. Identification of the incorrectly marked question (if it comes in the exam) is the phrase "weather clutter" in the question. There is another one which is correctly marked but it has the phrase "storm clutter" in the question.


Arrow Which of the following systems use pulse technique?

a) secondary surveillance radar
b) airborne weather radar
c) distance measuring equipment
d) primary radar

a) marked correct whereas all options use pulse technique.


Arrow What is the PRF given 50 micro second pulse width and a range of 30 nm:

a) 1620 pps
b) 810 pps
c) 3240 pps
d) 3086 pps

a) marked correct. There seems to be a typo in the question. With 30nm PRF comes out to be 2700, however with 50nm it is 1620.

There is another question in the database which is correct:

The maximum pulse repetition frequency (PRF) that can be used by a primary radar facility in order to detect targets unambiguously at a range of 50 NM is:

(pps = pulses per second)

a) 610 pps
b) 3240 pps
c) 1620 pps
d) 713 pps

c) is marked correct and is correct.

Identification of the incorrectly marked question (if it comes in the exam) is the appearance of the phrase "50 micro second pulse width". The 50 micro second pulse width given in the question does not affect the maximum range, but will determine the minimum range.


Arrow In the approach phase with a two dot lateral deviation HSI display, a one dot deviation from track would represent:

a) 5 nm
b) 0.5 nm
c) 5
d) 0.5

d) marked correct

If its the the RNAV Approach mode, maximum deflection of the CDI typically represents 1.25 NM on either side of the selected course. That makes one dot equal to 0.625 nm. This questions was deleted from the CQB years ago because they refer to a particular RNAV installation (no idea which) and have no generally correct answer.


Arrow What is the deviation per dot on the HSI when using a 2-dot RNAV system in the approach mode?

a) 10 NM
b) 0.5
c) 10
d) 0.5 NM

b) marked correct.

In the RNAV Approach mode, maximum deflection of the CDI typically represents 1.25 NM on either side of the selected course. That makes one dot equal to 0.625 nm. This questions was deleted from the CQB years ago because they refer to a particular RNAV installation (no idea which) and have no generally correct answer.


Arrow What is the deviation per dot on the HSI when using a 2-dot basic RNAV system in the en-route mode?

a) 1 NM
b) 5 NM
c) 2 NM
d) 10 NM

b) marked correct

If full scale deflection is 5 nm on one side then one dot should represent 2.5 nm. This questions was deleted from the CQB years ago because they refer to a particular RNAV installation (no idea which) and have no generally correct answer.


Arrow The principle of operation of LORAN C is:

a) differential range by phase comparison
b) differential range by pulse technique
c) range by pulse technique
d) range by phase comparison

a) marked correct whereas (b) is correct.

Identification of the incorrectly marked question (if it comes in the exam) is the phraseology of the question which strats with "The principle of operation". Other correctly marked questions are as under:

1) Which of the following correctly gives the principle of operation of the Loran C navigation system?

Differential range by phase comparison
Frequency shift between synchronised transmissions
Differential range by pulse technique
Phase comparison between synchronised transmissions

2) Which of the following statements concerning LORAN-C is correct?

It is a hyperbolic navigation system that works on the principle of range measurement by phase
It is a navigation system based on secondary radar principles; position lines are obtained in sequence from up to eight ground stations
It is a hyperbolic navigation system that works on the principle of differential range by pulse technique
It is a navigation system based on simultaneous ranges being received from a minimum of four ground stations

3) Which statement is most correct?

Loran C creates hyperbolic position lines based on differential range by pulse technique
Loran C creates hyperbolic lines based on a low sweep rate frequency modulated continuous wave
Loran C creates hyperbolic lines based on an atomic time standard
Loran C creates elliptical lines based on differential range by Doppler

4) Loran C is a navigation system which uses:

differential range measurements
rho/theta measurements
pseudo range measurements
slant range measurements


Arrow In what type of nominal orbit are NAVSTAR/GPS satellites placed?

a) Geo-stationary
b) Elliptical
c) Circular
d) Pole to pole

b) marked correct whereas (c) is correct.

A geostationary orbit, or Geostationary Earth Orbit (GEO), is a circular orbit 35,786 kilometres (22,236 mi) above the Earth's equator and following the direction of the Earth's rotation. An object in such an orbit has an orbital period equal to the Earth's rotational period (one sidereal day), and thus appears motionless, at a fixed position in the sky, to ground observers. Communications satellites and weather satellites are often given geostationary orbits, so that the satellite antennas that communicate with them do not have to move to track them, but can be pointed permanently at the position in the sky where they stay. A geostationary orbit is a particular type of geosynchronous orbit.


Arrow The orbital height of geostationary satellites is:

a) 15330 km
b) 20180 km
c) 10898 nm
d) 10313 nm

b) marked correct whereas (b) and (c) are almost the same except the units.


Arrow A microwave landing system operates:

a) on one of 200 channels in the band 5030 to 5090 GHz
b) on one of 200 channels in the band 5.03 GHz to 5090 GHz
c) on one of 400 channels in the band 5030 GHz to 5090 GHz
d) on one of 400 channels in the band 5.03 GHz to 5.09 GHz

b) marked correct whereas the correct answer is not given. It should be "one of 200 available channels in band 5031 MHz to 5090.7 MHz or 5.03 GHz to 5.09 GHz or a combination thereof" It cant be 5090 GHz.


Arrow When using a DVOR, the pilot should be aware that the reference and variable signals are reversed. This:

a) does not affect the VOR indications in any way
b) reverses the indications
c) improves the accuracy
d) improves the range

d) marked correct whereas out of the available options (c) is correct. C is also marked correct in other databases.
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roy



Joined: 08 Sep 2015
Posts: 8

PostPosted: Thu Sep 10, 2015 1:44 am    Post subject: Radio Navigation Reply with quote

Referring question 2,

Arrow At a height of 5,000 feet you might expect to receive a VHF signal, from a transmitter at sea level, at a range of:

a) 88,4 nm
b) 88,4 nm
c) 70,7 nm
d) 200 km

a) correct but both a) and b) are same.

..

In my book it says,

Arrow At a height of 5,000 feet you might expect to receive a VHF signal, from a transmitter at sea level, at a range of:

a) 88,4 km
b) 88,4 nm
c) 70,7 nm
d) 200 km
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K.Haroon
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Joined: 11 Dec 2005
Posts: 1305

PostPosted: Thu Sep 10, 2015 2:11 am    Post subject: Reply with quote

using the formula:

Max theoretical range = 1.23 x square root of H1 + 1.23 x square root of H2 (H1 and H2 are heights of transmitter and receiver).

the answer is in nautical miles
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roy



Joined: 08 Sep 2015
Posts: 8

PostPosted: Thu Sep 10, 2015 2:42 am    Post subject: Radio Navigation Reply with quote

Sorry for my typing mistake it was as following,

Arrow At a height of 5,000 feet you might expect to receive a VHF signal, from a transmitter at sea level, at a range of:

a) 88,4 nm
b) 88,4 km
c) 70,7 nm
d) 200 km

Is there a way to attach a picture ?
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K.Haroon
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Joined: 11 Dec 2005
Posts: 1305

PostPosted: Thu Sep 10, 2015 2:47 am    Post subject: Reply with quote

Yeah that's correct. The database I consulted had a typo so I just mentioned that. It may not apply to everyone.

N.B. The image for which you posted the link is on your desktop, it wont be visible unless it is online on some website
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roy



Joined: 08 Sep 2015
Posts: 8

PostPosted: Thu Sep 10, 2015 2:50 am    Post subject: Reply with quote

[img]https://drive.google.com/file/d/0B6xarfe1jwOod0ZhaTJnRVJKd1E/view?usp=sharing[/img]

Thank you Haroon
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K.Haroon
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Joined: 11 Dec 2005
Posts: 1305

PostPosted: Thu Sep 10, 2015 3:05 am    Post subject: Reply with quote

welcome however some how it is not embedding google drives image links here. in any case embedding images here is also not a great idea because different image sizes will distort the whole page. just post the image as a link i.e. instead og [img] and [/img] type [url] and [/url]. You can edit your post and correct.

you can also upload pics on the chat thing and then can use its link here.
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roy



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Posts: 8

PostPosted: Thu Sep 10, 2015 3:07 am    Post subject: Reply with quote

I will Haroon, thanks again.
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