Basics – Air – DGCA Question Bank For Politics

Results

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#1. Wavelength is the distance from?

Wave crest to wave crest

Trough to next wave crest

The E and H fields superimposed onto the system reactance background scatter

Wave crest to next trough.

#2. The emission characteristics A3E describe?

ILS

VOR

HF communications

VHF communications

#3. Electromagnetic waves travel at?

The speed of sound

300 000 metres per second

The speed of light

162 000 miles per hour.

#4. In regard to radio what does the term frequency mean?

The number of waveform in one hour.

The number of complete waveform passing a point in one second

The speed of radio waves in metres per second

The length of a complete waveform in metres.

#5. The Automatic Direction Finder (ADF) uses the following wavelength?

Metric

Decimetric

Centimetric

Hectometric or Kilometric

#6. According to ICAO Annex 10, in which frequency band(s) does a locator transmit?

LF/MF

HF/VHF

MF/HF

#7. The VHF Direction Finder uses the following wavelengths?

Hectometric

Decimetric

Metric

Centimetric

#8. The Instrument Landing System (ILS) uses the following wavelengths?

Hectometric

Decimetric

Metric

Centimetric

#9. The frequency band for the Automatic Direction Finder (ADF) is?

Hectometric

Decimetric

Metric

Centimetric

#10. The Microwave Landing System (MLS) uses the following wavelengths?

Myriametric

Metric

Hectometric

Centimetric

#11. Into what range does ILS localiser wavelength fall?

Kilometric

Metric

Nanometric

Millimetric

#12. A transmission of RF energy at a wavelength of 18 metres is in which frequency band?

VHF

#13. The distance Measuring Equipment (DME) uses the following wavelengths?

Decimetric

Metric

Hectometric

Centimetric

#14. The VHF Omnirange (VOR) uses the following wavelengths?

Decimetric

Metric

Hectometric

Centimetric

#15. What is the wavelength of the ILS Localiser signal?

Myriametric

Metric

Hectometric

Centimetric

#16. What is the wavelength of a VOR?

Decimetric

Metric

Hectometric

Centimetric

#17. Frequency is define as the?

Number of complete cycles recurring in one unit of time.

Distance between a crest and a crest

Number of complete cycles recurring in ten units of time

Distance from axis to peak value

#18. A radio facility transmits on a wavelength of 2.22 cm. The facility could be a ............. operating on a frequency of ........?

VDF, 135 MHz.

DME, 1350 MHz.

Doppler 13500 MHz.

Radio Altimeter 13500 kHz.

#19. The Marker beacons use the following wavelengths?

Myriametric

Metric

Hectometric

Centimetric

#20. The Secondary Surveillance Radar (SSR) uses the following wavelengths?

Myriametric

Decimetric

Hectometric

Centimetric

#21. The Low Altitude Radio Altimeter (RADALT) uses the following wavelengths?

Decimetric

Metric

Myriametric

Centimetric

#22. A radio transmitter modulator?

Tunes the aerial only

Ensures receiver compatibility

Couples the RF signal to an aerial

Superimposes an audio frequency signal (AF) onto a radio frequency signal (RF).

#23. SELCAL is an equipment that?

Functions as a frequency modulator.

Is coupled with TCAS II and is concerned with TA warnings systems.

Automatically receives incoming signals

Automatically transmits data signals.

#24. What is the wavelength corresponding to a frequency of 375 kHz?

8 metres

80 metres

800 metres

8000 metres.

#25. What is the wavelength corresponding to a frequency of 75 MHz?

4 metres.

40 metres.

7.5 metres.

75 metres.

#26. A wavelength of 8.5 metres corresponds to a frequency of?

2833.3 MHz.

3594.4 MHz.

28333 MHz.

35294 MHz.

#27. The VHF frequency band is in the?

3 to 30 kHz range.

30 to 300 kHz range.

3 to 30 MHz range

30 to 300 MHz range.

#28. The VHF frequency band is in the ?

3 to 30 kHz range.

30 to 300 kHz range.

3 to 30 MHz range.

30 to 300 MHz range.

#29. Assuming a wavelength of 1 centimetre, the frequency will be?

30 MHz.

0.3 GHz.

3.0 GHz.

30 GHz.

#30. Decimetric waves correspond to a frequency of?

300 to 3000 kHz.

3000 to 30000 kHz.

300 to 3000 MHz.

3000 to 30000 MHz.

#31. The wavelength of a radio signal transmitted at a frequency of 118.7 MHz?

2.53 metres.

25.3 metres

2.53 centimetres

25.3 centimetres

#32. The wavelength of a radio signal with a frequency of 121.95 MHz?

26.60 metres.

24.60 centimetres

2.46 centimetres

2.46 metres.

#33. In the diagram below what is the phase difference of the higher amplitude signal from the reference signal?

135 degrees.

225 degrees

315 degrees

045 degrees.

#34. What is the frequency corresponding to a wavelength of 12 centimetres is?

2500 kHz

2500MHz.

360 MHz.

3600 MHz.

#35. Assuming a frequency of 20 MHz, the wavelength will be?

1.25 metres.

12.5 metres

800 metres

80 metres

#36. What is the wavelength of a radio signal with a frequency of 375 kHz?

1.25 metres

12.5 metres

800 metres

80 metres

#37. A frequency of 2400 kHz is equivalent to a wavelength of?

8 metres.

0.8 metres

125 metres

105 metres

#38. The wavelength of a non-directional beacon (NDB) at a frequency of 300 kHz is?

1 metres

10 metres

100 metres

1000 metres

#39. The wavelength of a radio signal is 200 metres. What is its frequency?

1.5 kHz.

1.5 MHz.

1.5 GHz.

15 MHz.

#40. c A radio signal has a frequency of 3 GHz, What is its wavelength?

1 metres

10 centimetres.

100 centimetres.

1.0 centimetres.

#41. The VHF frequency band has a wavelength limit of?

100 m to 10 m.

1 m to 100 cm.

10 m to 1 m.

100 cm to 10 cm.

#42. In the diagram, the phase difference between the two signals is?

90 degrees

180 degrees

270 degrees.

360 degrees

#43. A half wave dipole aerial suitable for transmitting an RF signal at 18 MHz should have an effective length of?

8.33 metres

16.67 metres.

83.33 metres

166.67 metres.

#44. The gain of an aerial is its ability to?

Focus power

Compensate for attenuation

Transmit intelligence.

Overcome transmitter line resistance

#45. A horizontally polarised electromagnetic wave?

Has the E field horizontal.

Has the E field vertical

Has the Z field horizontal

Has the H field horizontal.

#46. Which of the folllowing statements is correct in respect to a RF signal?

The plane of polarisation is dictated by the oscillator unit in the transmitter.

The electrical component of the signal is parallel to the aerial.

The magnetic component of the signal is parallel to the aerial.

Both the electrical component and the magnetic component of the signal are parallel to the aerial.

#47. A radio wave with a horizontal magnetic component would be best received by a ......... aerial?

Vertical

Horizontal

Parabolic

Magnetic

#48. An electromagnetic wave has two types of energy field?

An H electrical field and an E magnetic field.

A Z electrical field and an H magnetic field.

A Z magnetic field and an E electrical field.

An E electrical field and an H magnetic field.

#49. Feeder lines are of the following types?

Co-axial-up to 3000 MHz, wave guides- above 3000 MHz.

Co-axial- above 3000 MHz, wave guides- up to 3000 MHz.

Co-axial-up to 300 kHz, wave guides- above 300 kHz.

Wave guides - up to 20 MHz, co-axial-above 20 MHz.

#50. Comparing a parabolic reflector with a flat plate antenna of the same size?

The flat plate has a considerably smaller beam width

The parabolic reflector has a considerably smaller beam width

The flat plate antenna generates less side lobes than the parabolic reflector

The parabolic reflector generates less side lobes that the flat plate antenna.

#51. What causes the so called "night effect"?

The difference in velocity of the EM waves over land and over sea at night.

A change in the direction of the plane of polarisation due to reflections in the ionosphere.

Interference between ground waves and space waves.

The absence of the surface wave at distances larger than the skip distance.

#52. A Doppler shift will occur?

If a receiver is moving during reception of transmission from a fixed position transmitter.

If a transmitter is moving during transmission to a fixed position.

When the distance between a transmitter and a receiver is changing during a transmission.

All of the options are correct.

#53. An apparent increase in the transmitted frequency which is proportional to the transmitter velocity will occur when?

Both transmitter and receiver move towards each other.

The transmitter moves away from the receiver.

The transmitter moves towards the receiver.

The receiver moves towards the transmitter.

#54. An apparent decrease in the transmitted frequency , which is proportional to the transmitter velocity, will occur when?

Both transmitter and receiver move away from each other.

The transmitter moves away from the receiver .

The transmitter moves towards the receiver.

The transmitter and the receiver move towards each other.

#55. When a transmitter is moving towards a receiver, the correct description of Doppler effect is?

There is an increase in apparent wavelength, which is independent of transmitter velocity.

There is a decrease in apparent wavelength , which is independent of transmitter velocity.

There is an increase in apparent wavelength , which is dependent of transmitter velocity transmitter velocity.

There is a decrease in apparent wavelength, which is dependent of transmitter velocity.

#56. . Refraction of an eletromagnetic radiation is?

Loss of power through reflection from objects.

The bending of its propagation path as it passes through or over areas of different electrical conductivity.

The loss of power as it passes through or over areas of different electrical conductivity.

Bending resultant from reflection from objects.

#57. Which statement is true?

The lower the frequency the greater the ionospheric attenuation.

The attenuation of an HF ground wave is worse over the land than over ice.

The ionosphere will attenuate and refract signals up to 30 GHz.

None of the above options are true.

#58. Attenuation of radio waves means?

The weakening of radiated waves.

The atmospheric bending of waves.

Only the scattering of waves in the troposphere.

Only the absorption of energy by the sea.

#59. The term Doppler shift refers to?

The change in speed measured at the receiver.

The change in angle measured at the receiver.

The change in depression angle measured at the receiver.

The change in frequency measured at the receiver.

#60. When an LF radio wave passes over the Earth's surface it?

Speeds up, picks up electrons and becomes stronger.

Slows down, picks up electrons and becomes stronger.

Slows down and is attenuated.

Speeds up and is attenuated.

#61. To establish and maintain effective HF communication, frequency at a given range?

Should be decreased at night.

Should be increased at night.

Should remain constant.

Should only be varied by season, decreased in summer and increased in winter.

#62. Skip distance is the?

Thickness of the ionosphere.

Highest critical frequency distance

Range from the transmitter to the first returning sky wave.

Wavelength distance of a certain frequency

#63. Diffraction of an FR signal is a displacement of its propagation path due to?

Passing through ionised regions of the upper atmosphere.

Reflection from the surface.

Passing over or through mediums of different conductivity.

Passing over obstacle with dimensions close to the wavelength.

#64. Using a medium frequency band when is fading likely to occur?

Night with sky and ground waves.

night time when snowing.

Day time when snowing.

Day with sky and ground waves.

#65. Complete the following statement. .....radio signals have a ..... range by ..... wave over ..... than over .....?

MF, shorter, sky, sea, land.

MF, greater, ground, sea, land.

VHF, shorter, sky, sea, land.

MF, greater, ground, land, sea.

#66. The skip distance of HF transmissions will increase with?

Lower frequency and lower position of the reflecting layer.

Lower frequency and higher position of the reflecting layer.

Higher frequency and higher position of the reflecting layer.

Higher frequency and lower position of the reflecting layer.

#67. Attenuation is a generic term for?

Loss of power but is only relevant to space waves.

increase in power.

refraction.

loss of power.

#68. Reflection from the ionospheric layers is used in the following radio frequencies?

VLF.

HF.

VHF.

UHF.

#69. MF fading is most common?

During the day due to the reception of both sky waves and ground waves.

During the day and during heavy rain.

At night and during heavy rain.

At night due to the reception of both sky waves and ground waves.

#70. As the frequency of a transmitter is increased, the range of the ground wave will?

Increase.

Decrease.

Decrease by night only.

Increase over the sea.

#71. Skip distance is longest by ..... and with a ..... frequency?

Day, low.

Day, high.

Night, low.

Night, high.

#72. Attenuation of a radio wave is the?

Reduction of its power by absorption, scattering or spreading.

Increase of its power by the combination of multi-path signals.

Change of its frequency by use of sidebands.

Change of amplitude by use of sidebands.

#73. A radio signal loses strength as the range from the transmitter increases. This effect is called?

Ducting.

Amplification.

Attenuation.

Refraction.

#74. In the propagation of MF waves, the phenomenon of FADING is particularly found?

By day and when raining.

At night and when raining.

By day due to the combination of sky waves and ground waves.

At night, due to the combination of sky waves and ground waves.

#75. Fading happens?

In daytime when ground waves and sky waves interfere with each other.

At night when ground waves and sky waves interfere with each other.

At night when the signal is received by ground waves only.

At daytime when the signal is received by sky waves only.

#76. Which of the following statements is true?

A transmission's bandwidth is affected by the design of the aerial.

Bandwidth must be reduced in order to reduce noise.

A narrow bandwidth improves beam width.

A broad bandwidth gives a narrow beam width.

#77. Diffraction is the process by which?

A direct wave is bend around the form of the Earth.

A space wave penetrates the ionosphere.

Radio waves travel over and around objects.

A ground wave is attenuated over rough ground.

#78. What is the lowest frequency where freedom from static interference can be guaranteed?

3 MHz.

30 MHz.

300 MHz.

3 GHz.

#79. An HF transmitter is tuned to a frequency that refracts from the E layer in the ionosphere. The maximum distance of the first returning sky wave is?

599 km.

1500 km.

599 nm.

1500 nm.

#80. The approximate maximum range of ground waves of LF and MF are (by day) ..... and .....respectively, with..... suffering more from atmospheric attenuation?

1500 nm, 1000nm, MF.

1000 nm, 500nm, LF.

1000 nm, 300nm, MF.

500 nm, 100nm, LF.

#81. An aircraft travelling at 300 metres per second transmits a radio signal at 10 GHz to a stationary receiver. If the aircraft is flying directly towards the receiver and they are approximately at the same height, the received signal frequency will be?

11 MHz.

10.000011 GHz.

9.999989 GHz.

11 GHz.

Finish

Dgca Question Bank For Pilots

Results

#1. Wavelength is the distance from?

#2. The emission characteristics A3E describe?

#3. Electromagnetic waves travel at?

#4. In regard to radio what does the term frequency mean?

#5. The Automatic Direction Finder (ADF) uses the following wavelength?

#6. According to ICAO Annex 10, in which frequency band(s) does a locator transmit?

#7. The VHF Direction Finder uses the following wavelengths?

#8. The Instrument Landing System (ILS) uses the following wavelengths?

#9. The frequency band for the Automatic Direction Finder (ADF) is?

#10. The Microwave Landing System (MLS) uses the following wavelengths?

#11. Into what range does ILS localiser wavelength fall?

#12. A transmission of RF energy at a wavelength of 18 metres is in which frequency band?

#13. The distance Measuring Equipment (DME) uses the following wavelengths?

#14. The VHF Omnirange (VOR) uses the following wavelengths?

#15. What is the wavelength of the ILS Localiser signal?

#16. What is the wavelength of a VOR?

#17. Frequency is define as the?

#18. A radio facility transmits on a wavelength of 2.22 cm. The facility could be a ............. operating on a frequency of ........?

#19. The Marker beacons use the following wavelengths?

#20. The Secondary Surveillance Radar (SSR) uses the following wavelengths?

#21. The Low Altitude Radio Altimeter (RADALT) uses the following wavelengths?

#22. A radio transmitter modulator?

#23. SELCAL is an equipment that?

#24. What is the wavelength corresponding to a frequency of 375 kHz?

#25. What is the wavelength corresponding to a frequency of 75 MHz?

#26. A wavelength of 8.5 metres corresponds to a frequency of?

#27. The VHF frequency band is in the?

#28. The VHF frequency band is in the ?

#29. Assuming a wavelength of 1 centimetre, the frequency will be?

#30. Decimetric waves correspond to a frequency of?

#31. The wavelength of a radio signal transmitted at a frequency of 118.7 MHz?

#32. The wavelength of a radio signal with a frequency of 121.95 MHz?

#33. In the diagram below what is the phase difference of the higher amplitude signal from the reference signal?

#34. What is the frequency corresponding to a wavelength of 12 centimetres is?

#35. Assuming a frequency of 20 MHz, the wavelength will be?

#36. What is the wavelength of a radio signal with a frequency of 375 kHz?

#37. A frequency of 2400 kHz is equivalent to a wavelength of?

#38. The wavelength of a non-directional beacon (NDB) at a frequency of 300 kHz is?

#39. The wavelength of a radio signal is 200 metres. What is its frequency?

#40. c A radio signal has a frequency of 3 GHz, What is its wavelength?

#41. The VHF frequency band has a wavelength limit of?

#42. In the diagram, the phase difference between the two signals is?

#43. A half wave dipole aerial suitable for transmitting an RF signal at 18 MHz should have an effective length of?

#44. The gain of an aerial is its ability to?

#45. A horizontally polarised electromagnetic wave?

#46. Which of the folllowing statements is correct in respect to a RF signal?

#47. A radio wave with a horizontal magnetic component would be best received by a ......... aerial?

#48. An electromagnetic wave has two types of energy field?

#49. Feeder lines are of the following types?

#50. Comparing a parabolic reflector with a flat plate antenna of the same size?

#51. What causes the so called "night effect"?

#52. A Doppler shift will occur?

#53. An apparent increase in the transmitted frequency which is proportional to the transmitter velocity will occur when?

#54. An apparent decrease in the transmitted frequency , which is proportional to the transmitter velocity, will occur when?

#55. When a transmitter is moving towards a receiver, the correct description of Doppler effect is?

#56. . Refraction of an eletromagnetic radiation is?

#57. Which statement is true?

#58. Attenuation of radio waves means?

#59. The term Doppler shift refers to?

#60. When an LF radio wave passes over the Earth's surface it?

#61. To establish and maintain effective HF communication, frequency at a given range?

#62. Skip distance is the?

#63. Diffraction of an FR signal is a displacement of its propagation path due to?

#64. Using a medium frequency band when is fading likely to occur?

#65. Complete the following statement. .....radio signals have a ..... range by ..... wave over ..... than over .....?

#66. The skip distance of HF transmissions will increase with?

#67. Attenuation is a generic term for?

#68. Reflection from the ionospheric layers is used in the following radio frequencies?

#69. MF fading is most common?

#70. As the frequency of a transmitter is increased, the range of the ground wave will?

#71. Skip distance is longest by ..... and with a ..... frequency?

#72. Attenuation of a radio wave is the?

#73. A radio signal loses strength as the range from the transmitter increases. This effect is called?

#74. In the propagation of MF waves, the phenomenon of FADING is particularly found?

#75. Fading happens?

#76. Which of the following statements is true?

#77. Diffraction is the process by which?

#78. What is the lowest frequency where freedom from static interference can be guaranteed?