Results
#1. Winds in a low pressure
similiar to a stream of water flowing from hill to the ground
Winds from a high pressure area travel towards a low pressure, to fill the void
in high pressure are wind diverges
in low pressure are wind converges
#2. Low pressure is associated with
In the low pressure area winds converge and there is a vertical movement of air and with abundance of moisture it is the perfect recipe for creation of cloud and bad weather
#3. In a high pressure area winds are
Winds in a high-pressure diverges unlike low pressure because of which there is no vertical movement hence better weather and bad visibility
#4. Flying from Low to High an altimeter would read
Imagine travelling from a low pressure area where you are at 10000 feet to high pressure area ,
refer the diagram,
you will be at an altitude below 10000 feet
hence
low pressure to high pressure you are at low altitude
use LOW HIGH LOW( under reading altimeter)
for high pressure to low pressure
HIGH LOW HIGH ( over reading altimeter)
#5. Isallobars are lines of equal
Line joining places of equal pressure = isobars
line joining places of equal pressure change ( tendencies)= ISALLOBAR
#6. What kind of a barometer is an altimeter
The meaning of ANEROID is using no liquid
The aneroid barometer does not contain mercury or liquid, but measures the effect of air pressure on a partially evacuated metal capsule
#7. A region between two Lows and Two Highs is
Cols are regions of almost level pressure between two highs and two lows. It is an area of stagnation
#8. Bad weather and better visibility is associated with
In the low pressure area winds converge and there is a vertical movement of air and with abundance of moisture it is the perfect recipe for creation of cloud and bad weather ,
because of the movement of air , there is no mist dust haze or any stagnation hence visibility is good
#9. The relationship between height and pressure is made use in construction of
With increase in height pressure reduces , this relation is used to determine the altitude of an aircraft using altimeter
#10. Altimeter always measure the height of aircraft above
The altimeter can be fed with
QNH which gives altitude
QNE (1013) which gives FLIGHT LEVEL
QFE which gives height
#11. Two aircraft flying at same indicated altitude with altimeters set to 1013.2 h.Pa. One is flying over cold air mass and other over warm air mass. Which of the two has greater altitude?
molecules in cold air are closely packed
molecules in warm air are loosely packed
a column of cold air on the left, and a column of warm air on the right. Notice that, since cold air causes pressure to fall more rapidly with height, the pressure levels in the cold air column are compressed towards the Earth’s surface, whereas, in the warm air column, they expand away from the surface.
#12. The rate of fall of pressure with height in a warm air mass compared to cold air mass will be
Cold air causes pressure to fall more rapidly with height.
Warm air causes pressure to fall more slowly with height.
a column of cold air on the left, and a column of warm air on the right. Notice that, since cold air causes pressure to fall more rapidly with height, the pressure levels in the cold air column are compressed towards the Earth’s surface, whereas, in the warm air column, they expand away from surface
#13. An increase of 1000 ft at msl is associated with decrease of pressure of
#14. Lines drawn through places of equal pressure are known as
Line joining places of equal pressure = isobars
line joining places of equal pressure change ( tendencies)= ISALLOBAR
#15. Which is true?
Trough is a low weather system
northern Hemisphere low pressure backs ( anti-clockwise) and opposite in SOUTHERN HEMISPHERE
#16. Semi diurnal pressure changes are most pronounced in
Semi diurnal variation of pressure are very small over poles and are large at the equator due to solar influence
tropics are close to equator
#17. Flying from Delhi to Kolkata at constant indicated altitude but, experiencing drift to Starboard. The actual altitude will be (vis-à-vis) indicated altitude.
In northern hemisphere
winds from LEFT Altimeter OVER READ
Winds from RIGHT altimeter UNDERREAD
The altitude indicated will be lower
#18. In the Southern Hemisphere, around a Low pressure Area wind blows
northern Hemisphere low pressure backs ( anti-clockwise) and opposite in SOUTHERN HEMISPHERE it is clockwise
#19. Altimeter of a/c on ground reads aerodrome elevation; its sub-scale is set to
The altimeter can be fed with
QNH which gives altitude
QNE (1013) which gives FLIGHT LEVEL
QFE which gives height
QNH which gives altitude from reference datum, in this case reference datum is Mean sea level
Hence you get airfield elevation from msl
#20. Instrument for recording pressure is called
BARO means pressure
ANEMO is used with wind
HYGRO relates to water
#21. Poor visibility is associated with
In a HIGH there is divergence of wind to low pressure region ,there is no vertical movement of air and fog mist or haze stands still hence poor visibility
#22. On either side, perpendicular to the ______ pressures rise
Centre of trough lowest pressure exists L ,On either side pressure is reducing keeping the lowest pressure along centre
#23. Fall of pressure with height is more rapid in
Cold air causes pressure to fall more rapidly with height.
Warm air causes pressure to fall more slowly with height.
a column of cold air on the left, and a column of warm air on the right. Notice that, since cold air causes pressure to fall more rapidly with height, the pressure levels in the cold air column are compressed towards the Earth’s surface, whereas, in the warm air column, they expand away from surface
#24. 300 hPa in ISA corresponds to the level
Refer to the chart
PRESSURE ALTITUDE FOR 300 hpa is 30000
#25. 18,000 ft height in ISA corresponds to the pressure level
Refer to chart
PRESSURE ALTITUDE OF 18000 is 500 hpa
#26. 200 hPa in ISA corresponds to the level
Refer to chart
PRESSURE ALTITUDE OF 38000 is 200 hpa
choose the closest
#27. 24,000 ft height in ISA corresponds to pressure level
Refer to chart
PRESSURE ALTITUDE OF 24000 is 400 hpa
#28. 700 hPa in ISA corresponds to the Fight level
Refer to chart
PRESSURE ALTITUDE OF 10000 is 700 hpa
choose the closest
#29. 40,000 ft height in ISA approximately corresponds to pressure level
Refer to chart
PRESSURE ALTITUDE OF 40000 is 200 hpa
#30. 850 hPa in ISA approximately corresponds to the height
Refer to chart
PRESSURE ALTITUDE OF 5000 is 850 hpa
#31. Atmospheric pressure is due to
Atmospheric pressure is caused by the weight of the Earth’s atmosphere
The density of air decreases with height. There are two reasons: at higher altitudes, there is less air pushing down from above, and gravity is weaker farther from Earth’s center
#32. An aircraft is gaining altitude, inspite of altimeter reading constant altitude. Why?
Altimeter is still showing the previous altitude which is less than the actual so,
it is under reading
low pressure to high pressure you are at low altitude
use LOW HIGH LOW( under reading altimeter)
for high pressure to low pressure
HIGH LOW HIGH ( over reading altimeter)
#33. An contour of 9160 m can be expected on a constant pressure chart of pressure level
1 metre is 3.2 feet
which makes 9160 meter = 30000 feet
using above chart
30000 pressure altitude is 300 hpa
#34. In contour chart of 300 hPa, isohypse (contours) are drawn at interval of
GPM is unit of contour charts the contours are drawn at an interval of 40 GPM in 700 Hpa and 500 hpa level charts and at 80 GPM in 300 Hpa and 200 Hpa level charts
#35. In constant pressure chart of 500 hPa, isohypse are drawn at interval of
GPM is unit of contour charts the contours are drawn at an interval of 40 GPM in 700 Hpa and 500 hpa level charts and at 80 GPM in 300 Hpa and 200 Hpa level charts
#36. QNH of an aerodrome 160 m AMSL is 1005 hPa. QFE? Assuming 1hPa = 8m
If you set QNH you get elevation
if you set QFE you get height of the airfield from the aircraft
In this case airfield is 160 metres above msl
if at sea level pressure is 1005 hpa how much pressure 160 metres above(airfield)
If
1 hpa= 8 meter
then 20 hpa = 160 meter
so reduce 20 hpa from 1005 hpa
( pressure reduces with height)
answer 985 hpa
#37. Steep pressure gradient would mean
Pressure gradient is the horizontal rate of change of pressure perpendicular to be isobars directed from high to low pressure it is steep or weak according to the isobars are close or far apart it is said to be steep isobars are closely packed
#38. What type of inversion occurs when a stable layer lies in a high pressure area
As the air descends in a high pressure system it becomes compressed. This compression causes the air to warm and thus prevents any significant cloud from forming (because to make clouds, air must cool). The other effect of this warming is to create a “foot” of abnormally warm air at the bottom of the high pressure system. This foot of warm air sits a few thousand feet above the surface and creates a temperature inversion commonly called a subsidence inversion.
#39. Which of the following would cause true altitude to increase when altimeter indicates constant altitude?
if altimeter is showing lower altitude than the actual altitude , it could be flying from
LOW PRESSURE TO HIGH PRESSURE -under read
LOW HIGH- LOW
OR
COLD TO HOT – under read
#40. The movement of wind in relation to a cyclone is
Cyclone is a low pressure system
In the low pressure area winds converge and there is a vertical movement of air and with abundance of moisture it is the perfect recipe for creation of cloud and bad weather
#41. An aerodrome is at the mean sea level. Its QNH is 1014.0 hPa. Its QFF will be
