AIR MASSES – Air – DGCA Question Bank For Politics

#1. What will be the effect on the reading of an altimeter of an aircraft parked on the ground shortly before an active cold front passes?

It will be increasing.

It will remain unchanged.

It will be decreasing.

It will fluctuate up and down by about +/- 50 feet.

As the cold air advances, it forces the warm air upwards causing the warm air to cool. The water vapour in the warm air mass, consequently, condenses, and clouds are created. The slope of the cold front boundary is steeper than that of the warm front, with a gradient of approximately one in fifty.

The unstable air just ahead of the cold front is, forced to rise vigorously. Causing pressure to reduce and altimeter reading increased

#2. In which approximate direction does the centre of a frontal depression move?

In the direction of the warm sector isobars.

In the direction of the isobars ahead of the warm front.

In the direction of the sharpest pressure increase.

In the direction of the isobars behind the cold front.

the whole of the polar front depression will move as the warm front and cold fronts move and will in fact narrow, as the cold front moves faster than the warm. The depression at the tip of the warm sector will move parallel to the isobars in the warm sector at a speed given by the distance between the first and second isobars.

#3. The cold front is indicated with a number at position:

2

1

3

4

triangles,are the standard symbols denoting a cold front.

hence 4

semi-circular Are denoting warm front

#4. The main factor which contributes to the formation of very low clouds ahead of a warm front is the

saturation of the cold air by rain falling into it and evaporating

saturation of the warm air by rain falling into it and evaporating

reduction of outgoing radiation due to clouds

warm air moving over a cold surface

Because the warm air is being forced upwards into lowering atmospheric pressure, the air expands and cools. Water vapour in the air, therefore, condenses, creating cloud along the frontal boundary. The cloud takes on a horizontal, layered appearance since the slope of the warm front is about one in one hundred and fifty, much shallower than the slope indicated in the diagram This layer-type cloud is called stratiform cloud.

#5. A squall line usually is most likely to be encountered

at an occluded front

in an air mass with cold mass properties

behind of a stationary front

ahead of a cold front

#6. When do cold occlusions occur most frequently in Europe?

Summer

Winter

Autumn and winter

Winter and spring

#7. When do cold occlusions occur most frequently in Europe?

Summer

Winter

Autumn and winter

Winter and spring

#8. The polar front is the boundary between:

polar air and tropical air.

arctic air and polar air.

arctic air and tropical air.

maritime polar air and continental polar air.

#9. Which of the following is typical for the passage of a cold front in the summer ?

Rapid increase in temperature once the front has passed

Mainly towering clouds

Mainly layered clouds

Rapid drop in pressure once the front has passed

#10. The warm sector is indicated by letter:

A

B

C

D

#11. In which air mass are extremely low temperatures encountered?

Arctic maritime air.

Polar continental air.

Polar maritime air.

Tropical continental air

#12. What characterizes a stationary front?

The warm air moves at approximately half the speed of the cold air

The weather conditions that it originates is a combination between those of an intense cold front and those of a warm and very active front

The surface wind usually has its direction parallel to the front

The surface wind usually has its direction perpendicular to the front

#13. What type of front / occlusion usually moves the fastest?

Warm occlusion.

Cold front.

Warm front.

Cold occlusion

#14. What will be the effect on the reading of an altimeter of an aircraft parked on the ground during the period following the passage of an active cold front?

It will show a small increase or decrease.

It will have decreased.

It will remain unchanged.

It will have increased.

#15. Where does polar continental air originate?

Siberian landmass.

Areas of arctic water.

The region of the Baltic sea.

The region of Greenland

#16. After passing at right angles through a very active cold front in the direction of the cold air, what will you encounter, in the northern hemisphere immediately after a marked change in temperature?

A veering in the wind direction

A backing in the wind direction

An increase in tailwind

A decrease in headwind

#17. In which of the following regions does polar maritime air originate?

Baltic Sea

Black Sea

East of Greenland

Region of British Isles

#18. How do air masses move at a warm front?

Cold air overrides a warm air mass

Cold air undercuts a warm air mass

Warm air undercuts a cold air mass

Warm air overrides a cold air mass

#19. What types of cloud will you meet flying towards a warm front?

At some 500 km from the front, groups of CB, later at some 250 km thickening AS

At some 800 km CS, later AS, and at some 300 km NS until the front

Extensive areas of fog. At some 100 km from the front NS begin

At some 500 km AS, later CS and at some 80 km before the front CB

#20. (For this question use annex A) Refer to the diagram. Assuming the usual direction of movement, to which position will the polar frontal wave have moved?

Position 1

Position 4

Position 3

Position 2

#21. In which main direction does a polar front depression move?

Across the front towards the north

Across the front towards the south

Along the front towards the east

Along the front towards the west

#22. The front labeled “1” is a:

Warm front

Cold front

Warm front occlusion

Cold front occlusion

#23. How are the air masses distributed in a cold occlusion ?

The coldest air mass behind and the less cold air in front of the occlusion; the warm air mass is above ground level

The coldest air in front of and the less cold air is behind the occlusion; the warm air mass is above ground level

The coldest air in front of and the warm air behind the occlusion; the less cold air is above ground level

The coldest air behind and the warm air in front of the occlusion; the less cold air mass is above ground level

#24. (For this question use annex F) Which typical weather situation is shown on the weather chart? (Spacing of the isobars: 5 hPa)

Cutting wind

West wind condition

Warm south wind condition (Foehn)

Uniform pressure pattern.

#25. (For this question use annex B) Refer to the diagram. Assuming the usual direction of movement, where will this polar frontal wave have moved?

Position 2

Position 4

Position 3

Position 1

#26. Where is the coldest air to be found, in an occlusion with cold front characteristics?

At the surface position of the front.

At the junction of the occlusion.

Behind the front.

Ahead of the front.

#27. What cloud cover is typical for a wide warm sector of a polar front depression over Central Europe in the summer ?

Fair weather CU

BKN CU and CB

Sky clear

ST with drizzle

#28. A frontal depression passes through the airport. What form of precipitation do you expect?

Rain or snow during about 12 hours until the warm front arrives. Within the warm sector the rain increases. Improvement on the passage of the cold front

Continuous rain or snow during 6 hours until the warm front arrives. The precipitation stops for several hours within the warm sector. On the arrival of the cold front, showers within a couple of hours

Continous rain or snow while the frontal wave passes for a period of some 24 hours.

Showers during some 2 hours until the warm front arrives. Drizzle in the warm sector within 12 hours. Rain or snow on the passage of the cold front.

#29. At the approach of a warm front (northern hemisphere) the wind direction changes from the surface up to the tropopause. The effect of this change is that the wind

backs in the friction layer and and backs above the friction layer

veers in the friction layer and veers above the friction layer

backs in the friction layer and veers above the friction layer

veers in the friction layer and backs above the friction layer

#30. (For this question use annex C) Which cross-section of air mass and cloud presentation is applicable to the straight line A-B?

4

3

2

1

#31. What is the surface visibility most likely to be, in a warm sector of tropical maritime air, during the summer?

Very good (greater than 50 km).

Moderate (several km).

Very poor (less than 1 km).

Good (greater than 10 km).

#32. On an aerodrome, when a warm front is approaching

QFE increases and QNH decreases.

QFE decreases and QNH increases.

QFE and QNH decrease.

QFE and QNH increase.

#33. During a cross-country flight at FL 50, you observe the following sequence of clouds: Nimbostratus, Altostratus, Cirrostratus, Cirrus. Which of the following are you most likely to encounter?

Strong, gusty winds.

A strong downdraught.

Increasing temperatures.

Decreasing temperatures.

#34. How do you recognize a cold air pool?

A cold air pool may only be recognized on the surface chart as a high pressure area.

As a low pressure area aloft (e.g. on the 500 hPa chart).

As a high pressure area aloft (e.g. on the 500 hPa chart).

A cold air pool may only be recognized on the surface chart as a low pressure area.

#35. What is encountered during the summer, over land, in the centre of a cold air pool?

Nothing (CAVOK).

Showers and thunderstorms.

Strong westerly winds.

Fine weather CU.

#36. Which of the following describes a warm occlusion?

The warmer air mass is ahead of the original warm front

The coldest air mass is ahead of the original warm front

The air mass behind the front is more unstable than the air mass ahead of the front

The air mass ahead of the front is drier than the air mass behind the front

#37. Thunderstorms can occur on a warm front if the

warm air is moist and the environmental lapse rate exceeds the saturated adiabatic lapse rate

cold air is moist and the environmental lapse rate is less than the dry adiabatic lapse rate

warm air is moist and the environmental lapse rate is less than the saturated adiabatic lapse rate

cold air is moist and the environmental lapse rate exceeds the saturated adiabatic lapse rate

#38. What is the relative movement of the two air masses along a cold front?

Cold air slides over a warm air mass

Warm air pushes under a cold air mass

Cold air pushes under a warm air mass

Warm air pushes over a cold air mass

#39. What type of precipitation would you expect at an active unstable cold front?

Freezing rain

Light to moderate continuous rain

Drizzle

Showers associated with thunderstorms

#40. Frontal depressions can be assumed to move in the direction of the 2000 feet wind

behind the cold front

at the apex of the wave

in the warm sector

in front of the warm front

#41. Read this description: “After such a fine day, the ring around the moon was a bad sign yesterday evening for the weather today. And, sure enough, it is pouring down outside. The clouds are making an oppressively low ceiling of uniform grey; but at least it has become a little bit warmer.” Which of these weather phenomena is being described?

A blizzard

Weather at the back of a the cold front

A cold front

A warm front

#42. What are the typical differences between the temperature and humidity between an air mass with its origin in the Azores and an air mass with its origin over northern Russia?

The North-Russian air is colder and more humid than the air of the Azores.

The air of the Azores is warmer and dryer than the North- Russian air.

The North-Russian air is warmer and dryer than the air of the Azores.

The air of the Azores is warmer and more humid than the North-Russian air

#43. (For this question use annex D) Examining the pictures, on which one of the tracks (dashed lines) is this cross-section to be expected?

Track A-D

Track A-E

Track B-D

Track B-C

#44. (For this question use annex E) Under the weather conditions depicted, which of the following statements is likely to apply?

Moderate to strong Foehn in the Alps.

Radiation fog is unlikely in Central Europe in the winter.

Thunderstorms may occur in the summer months over South West Europe.

Severe gradient wind likely over Central Europe.

#45. What cloud formation is most likely to occur at low levels when a warm air mass overrides a cold air mass?

Nimbostratus.

Cumulus.

Altostratus.

Cumulonimbus.

#46. Which of the following conditions are you most likely to encounter when approaching an active warm front at medium to low level ?

Severe thunderstorms at low altitude.

Extreme turbulence and severe lightning striking the ground.

High cloud base, good surface visibility, and isolated thunderstorms.

Low cloud base and poor visibility.

#47. The approximate inclined plane of a warm front is:

1/150

1/50

1/300

1/500

#48. Thunderstorms in exceptional circumstances can occur in a warm front if

the cold air is convectively stable.

the warm air is convectively stable.

the warm air is convectively unstable.

the cold air is convectively unstable.

#49. Which of the following zones is most likely to encounter little or no precipitation?

Frontal zones.

Occlusions.

The north side of the alps with a prevailing Foehn from the south.

The north side of the alps with a prevailing Foehn from the north.

#50. What will be the effect on the reading of an altimeter of an aircraft parked on the ground as an active cold front is passing?

It will remain unchanged.

It will first decrease then increase.

It will fluctuate up and down by about +/- 50 feet.

It will first increase then decrease.

#51. Which of the following statements concerning the core of a polar front jet stream is correct?

It and its surface projection lie in the warm air

It lies in the warm air; its pressure surfaces are horizontal at the height of the core

It lies in the cold air; the thermal wind reverses direction at the height of the core

It lies at a height where there is no horizontal temperature gradient; the slope of the pressure surfaces at the height of the core is at its maximum

Dgca Question Bank For Pilots

Results

#1. What will be the effect on the reading of an altimeter of an aircraft parked on the ground shortly before an active cold front passes?

#2. In which approximate direction does the centre of a frontal depression move?

#3. The cold front is indicated with a number at position:

#4. The main factor which contributes to the formation of very low clouds ahead of a warm front is the

#5. A squall line usually is most likely to be encountered

#6. When do cold occlusions occur most frequently in Europe?

#7. When do cold occlusions occur most frequently in Europe?

#8. The polar front is the boundary between:

#9. Which of the following is typical for the passage of a cold front in the summer ?

#10. The warm sector is indicated by letter:

#11. In which air mass are extremely low temperatures encountered?

#12. What characterizes a stationary front?

#13. What type of front / occlusion usually moves the fastest?

#14. What will be the effect on the reading of an altimeter of an aircraft parked on the ground during the period following the passage of an active cold front?

#15. Where does polar continental air originate?

#16. After passing at right angles through a very active cold front in the direction of the cold air, what will you encounter, in the northern hemisphere immediately after a marked change in temperature?

#17. In which of the following regions does polar maritime air originate?

#18. How do air masses move at a warm front?

#19. What types of cloud will you meet flying towards a warm front?

#20. (For this question use annex A) Refer to the diagram. Assuming the usual direction of movement, to which position will the polar frontal wave have moved?

#21. In which main direction does a polar front depression move?

#22. The front labeled “1” is a:

#23. How are the air masses distributed in a cold occlusion ?

#24. (For this question use annex F) Which typical weather situation is shown on the weather chart? (Spacing of the isobars: 5 hPa)

#25. (For this question use annex B) Refer to the diagram. Assuming the usual direction of movement, where will this polar frontal wave have moved?

#26. Where is the coldest air to be found, in an occlusion with cold front characteristics?

#27. What cloud cover is typical for a wide warm sector of a polar front depression over Central Europe in the summer ?

#28. A frontal depression passes through the airport. What form of precipitation do you expect?

#29. At the approach of a warm front (northern hemisphere) the wind direction changes from the surface up to the tropopause. The effect of this change is that the wind

#30. (For this question use annex C) Which cross-section of air mass and cloud presentation is applicable to the straight line A-B?

#31. What is the surface visibility most likely to be, in a warm sector of tropical maritime air, during the summer?

#32. On an aerodrome, when a warm front is approaching

#33. During a cross-country flight at FL 50, you observe the following sequence of clouds: Nimbostratus, Altostratus, Cirrostratus, Cirrus. Which of the following are you most likely to encounter?

#34. How do you recognize a cold air pool?

#35. What is encountered during the summer, over land, in the centre of a cold air pool?

#36. Which of the following describes a warm occlusion?

#37. Thunderstorms can occur on a warm front if the

#38. What is the relative movement of the two air masses along a cold front?

#39. What type of precipitation would you expect at an active unstable cold front?

#40. Frontal depressions can be assumed to move in the direction of the 2000 feet wind

#42. What are the typical differences between the temperature and humidity between an air mass with its origin in the Azores and an air mass with its origin over northern Russia?

#43. (For this question use annex D) Examining the pictures, on which one of the tracks (dashed lines) is this cross-section to be expected?

#44. (For this question use annex E) Under the weather conditions depicted, which of the following statements is likely to apply?

#45. What cloud formation is most likely to occur at low levels when a warm air mass overrides a cold air mass?

#46. Which of the following conditions are you most likely to encounter when approaching an active warm front at medium to low level ?

#47. The approximate inclined plane of a warm front is:

#48. Thunderstorms in exceptional circumstances can occur in a warm front if

#49. Which of the following zones is most likely to encounter little or no precipitation?

#50. What will be the effect on the reading of an altimeter of an aircraft parked on the ground as an active cold front is passing?

#51. Which of the following statements concerning the core of a polar front jet stream is correct?