Questions Flashcards
Lowest layer of atmosphere is
a) Troposphere
b) Tropopause
c) Stratosphere
Troposphere
Height of Tropopause at equator is
a) 10-12 km
b) 16-18 km
c) 12-14 km
16-18 km
Height of Tropopause at Poles is
a) 12-14 km
b) 12-13 km
c) 08-10 km
08-10 km
Higher the surface temperature…….. would be the tropopause
a) Higher
b) Lower
c) Same
Higher
Height of tropopause……..
a) Is constant
b) Varies with altitude
C) Varies with Latitude
Varies with Latitude
Above 8 km the lower temperatures are over
a) Equator
b) Mid Latitudes
c) Poles
Equator
Atmosphere is heated by
a) Solar Radiation
b) Heat from earth surface
c) From above
Heat from earth surface
Tropos means……
a) Turning
b) Under current
c) Convection
Turning
CO2 and H20 are also called
a) Green House Gases
b) Rare Earth Gases
Green House Gases
Troposphere is generally
a) Stable
b) Unstable
c) Neutral
Unstable
Stratosphere is
a) Unstable
b) Neutral
c) Stable
Stable
Tropopause is discontinuous at about
a) 30°lat
b) 40° lat
c) 60°lat
40° lat
Most of atmospheric mass is contained in …
a) Troposphere
b) Stratosphere
c) Heterosphere
Troposphere
Stratosphere extends from Tropopause to
a) 50 km
b) 60 km
c) 40 km
50 km
The middle atmosphere layer characterised by temperature inversion and stability…
a) Troposphere
b) Tropopause
c) Stratosphere
Stratosphere
Mother of pearl clouds occur in.
a) Mesosphere
b) Thermosphere
c) Stratosphere
Stratosphere
The temperature in ISA at 17 km is..
a) -56.5°C
b) -65.5° C
c) -35.5° С
-56.5°C
By weight, approximate ratio of 02 to N2 in the atmosphere is
a) 1:3
b) 1:4
c) 1:5
1:3
By volume, the approximate ratio of 02 to N2 in the atmosphere is
a) 1:3
b) 1:4
c) 1:5
1:4
By volume, the proportion CO2 in the atmosphere is
a) 3%
b) 0.3%
c) 0.03%
0.03%
In ISA, the mean sea level temperature is
a) 15° C
b) 10° C
c) 25°C
15° C
Maximum concentration of ozone is at a height of….
a) 10-15 km
b) 20-25 km
c) 30-35 km
20-25 km
Additional oxygen is needed while flying above
a) 5000 ft
b) 7000 ft
c) 10000 ft
10000 ft
CO2 and H20 keep the atmosphere
a) Warm
b) Cold
c) Have no effect
Warm
Noctilucent clouds occur in
a) Thermosphere
b) Mesosphere
c) Stratosphere
Mesosphere
Temperature at 2 km is 05 °C what is ISA deviation. Hint : (Actual-ISA)
a) -05°C
b) -02° C
e) - 03°C
- 03°C
Pressure at MSL is 1002.25 hPa. Find the ISA deviation. Hint : (Actual-ISA)
a) -11 hPa
b) 10 hPa
c) 12 hPa
-11 hPa
In actual atmosphere temp, at 19 km is -60°C. How much it differs from ISA deviation?
a) -4.5°C
b) -05.5° C
c) -03.5°C
-03.5°C
Nacreous clouds occur in
a) Thermosphere
b) Mesosphere
c) Upper Stratosphere
Upper Stratosphere
The atmosphere up to 80 km has a nearly similar composition and is called the Homosphere. Its uniform composition is due to.
a) Pressure
b) Gravitation of earth
C) Mixing due to Turbulence
Gravitation of earth
Half of the atmosphere, air mass is contained…….. below
a) 20,000 ft
b) 15,000 ft
c) 10,000 ft
20,000 ft
In jet standard atmosphere the Lapse rate is
a) 2° С/1000 ft
b) 2° C/km
c) 5 ° C/km
The rate of fall of temperatures with height, called
a) Isothermal rate
b) Inversion rate
c) Lapse rate
In actual atmosphere the lapse rate could
a) assume any value
b) fall up to 8 km
c) rise up to 30 km
Tropical Tropopause extends from the equator to lat 35° - 45º. over India it is at
a) 20 - 21 km
b) 14 - 15 km
c) 16 - 16.5 km
Lapse rate in the troposphere is produce by… . and in the stratosphere by…..
a) evaporation; condensation
b）Rising air; solar radiation
c) terrestrial radiation; solar radiation; convection
d) solar radiation; convection
Most of the water vapour in the atmosphere is confine upto
a) Stratosphere
b) 30,000 ft
c) mid troposphere
d) lower troposphere
Negative lapse rate of temperature is
a) Isothermal rate
b) temperature rise with lowering height
c) temperature rise with increase in height (INVERSION)
d) temperature fall with height
In ICAO ISA the atmosphere is assumed to be isothermal
a) In stratosphere
b) 11 to 16 km
c) 11 to 20 km
d)11 to 32 km
One of the Characteristics of our atmosphere is
A) poor conductor of heat and electricity
b) equator is warmer than poles above 10 km
c) lapse rate in the stratosphere is positive
d) density is constant above 8 km
Heat transfer in the atmosphere is maximum due to
A) convection
b) radiation
c) sensible heat
D) latent heat
The knowledge of the height of tropopause is important for a pilot because
a) weather is mainly confined up to this level.
b) clouds rarely reach up to this height due to jetstreams.
C) stratosphere start at this height where all solar radiation are absorbed
In ISA atmosphere the tropopause occurs at a height of
a) 8 - 10 km
B) 11 km
C) 16 - 18 km
044) Lapse rate in the troposphere is due to……. and is the Stratosphere is due to …..
a) Conduction, convection
b) terrestrial radiation, solar radiation
c) Rising air, solar radiation
d) Water vapour, Ozone.
There is reversal of temperature in the atmosphere at 8 km because
a) Lase rate at poles is always higher than at equator
b) Lapse rate at equator is always higher than at poles
C) Lapse rate at equator is always higher than at poles
d) Lapse rate reverses at poles and becomes negative
- ATMOSPHERIC PRESSURE
Winds in a low pressure
a) Converge
b) Diverge
c) Go straight
Low pressure is associated with
a) Good Weather
b) Bad Weather
c) None
In a high pressure area winds are
a) Normal
b) Strong
c) Weak
Flying from Low to High an altimeter would read
a) Over
b) Under
c) constant
Isallobars are lines of equal
a) Pressure
b) Temperature Tendency
c) Pressure Tendency
What kind of a barometer is an altimeter?
a) Aneroid
b) Mercury
c) Alcohol
A region between two Lows and Two Highs is
a) Depression
b) Secondary Low
c) Col
Bad weather and better visibilitv is associate with
A) High
b) Low
c) Col
The relationship between height and pressure is made use in construction of
a) Altimeter
b) ASI
c) VSI
Altimeter always measure the height of aircraft above
a) MSL
b) datum level of 1013.2 hPa
c) datum level at which it’s sub-scale is set
Two aircraft flying at the same indicated altitude with their altimeter set to 1013.2 hPa. One is flying over cold air mass and other over warm air mass. Which of the two has greater altitude?
a) Ac flying over warm air mass
b) Ac flying over cold air mass
The rate of fall of pressure with height in a warm air mass compared to cold air mass will be
a) Same
b) More
c) Less
An increase of 1000 ft at msl is associated with decrease of pressure of
a) 100 hPa
b) 1000 hPa
c) 3 hPa
d) 33 hPa
Lines drawn through places of equal pressure are known as
a) Isobars
b) Isotherms
c) Isogonal
d) Isoclinal
Which is true
a) Trough has frontal characteristics
b) At trough winds back in N - hemisphere
c) At trough winds veer in N- hemisphere
Semi Diurnal pressure changes are most pronounced in
a) Polar region
b) Middle latitudes
c) Tropics
Flying from Delhi to Calcutta at constant indicated altitude but, experiencing a drift to Starboard. The actual altitude will be (Vis-a-vis) indicated altitude
a) Lower
b) Same
c) Higher
In the Southern Hemisphere, around a Low Pressure Area wind blows
a) In clockwise direction
b) In anticlockwise direction
c) Across isobars towards the centre
Altimeter of a/c on ground reads aerodrome elevation, its sub-scale is set to
A) QNH
b) QNE
c) QFF
d) QFE
Instrument for recording pressure is called
a) Anemograph
b) Barometer
c) Hygrograph
Poor visibility is associated with
a) High
b) Low
c) Col
On either side, perpendicular to the ………. pressures rise
a) Trough
b) Ridge
c) Low
Fall of pressure with height is more rapid in
a) Cold areas
b) Warm areas
c) Humid areas
300 hPa in ISA corresponds to the level
a) 20,000 ft
b) 30,000 ft
c) 35,000 ft
18,000 ft height in ISA corresponds to level
a) 700 hPa
b) 200 hPa
c) 500 hPa
200 hPa in ISA corresponds to the level
a) 20,000 ft
b) 30,000 ft
c) 40,000 ft
24,000 ft height in ISA corresponds to level
a) 400 hPa
b) 500 hPa
c) 300 hPa
700 hPa in ISA corresponds to the level
a) 20,000 ft
b) 10,000 ft
c) 18,000 ft
40,000 ft height in ISA corresponds to level
a) 400 hPa
b) 500 hPa
c) 200 hPa
850 hPa in ISA corresponds to the level
a) 7,000ft
b) 5,000 ft
c) 10,000 ft
Atmospheric pressure is due to
a) wind
b) temperature
C) gravity
d) density
An aircraft is gaining altitude, inspite of altimeter reading constant altitude. why?
a) Standard pressure has risen
b) Flying towards High
C) Flying Towards Low
d) Temperature has decreased
A contour of 9160 m can be expected on a constant pressure chart for pressure level
a) 500 hpa
b) 400 hpa
c) 300 hpa
d) 200 hpa
In contour chart of 300 hpa, isohypse (contours) are drawn at interval of
a) 20 gpm
B) 40 gpm
C) 60 gpm
d) 80 gpm
In constant pressure chart of 500 hpa, isohypse are drawn at interval of
a) 20 gpm
b) 40 gpm
c) 60 gpm
D) 80 gpm
QNH of an aerodrome 160 m AMSL is 1005 hpa. QFE? (Assuming 1 hpa = 8 m )
a) 1010 hpa
b) 975 hpa
c) 1005 hpa
D) 990 hpa
Steep Pressure gradient would mean
a) Contours far apart and weak wind
b) Contours far apart and strong wind
c) Isobars far apart and temperature low
d) Isobars closely packed and strong wind
What type of inversion occurs when a stable layer lies in a high pressure area
a) Negative
b) Radiation
c) Subsidence
d) Airmass
Which of the following would cause true altitude to increase when altimeter indicates constant altitude
a) Warm/Low
b) Cold/Low
c) Hot/High
d) Cool/Low
The movement of wind in relation to a cyclone is
a) Descending and subsiding
b) Ascending and converging
c) Descending and cooling
d) Ascending and diverging
An aerodrome is at the mean sea level. Its QNH is 1014.0 hpa. Its QFF will be
a) 1014.0 hpa
b) 1013.25 hpa
c) Difficult to tell
d) More than QNH
- TEMPERATURE
Diurnal variation of temperature is greatest when wind is
a) calm
b) light
c) strong
calm
Diurnal variation of temperature is maximum over
a) forest
b) ocean
c) land
land
On a clear day the amount of solar radiation received by earth surface is
a) 3/4 th
b) 30%
c) 5/6 th
5/6 th
ALBEDO is
a) Radiation received by earth
b) Amount of heat
c) Reflecting power of earth
Reflecting power of earth
During Day the ambient temperature is … than ground
a) Lower
b) Higher
c) Same
Lower
Diurnal variation of temperature over ocean is …
a) More than land
b) Above 3°C
c) Less than 1°C
Less than 1°C
At a coast station the diurnal variation of temperature, depends on
a) Wind direction
b) Wind speed
c) Radiation
Wind direction
Snow surface reflects about……. % of solar radiation.
a) 75%
b) 80%
c) 90%
80%
Amount of Solar radiation received per unit area is …..
a) Insolation
b) Convection
c) Radiation
Insolation
Solar radiation received by the earth is …..
a) Long Wave
b) Albedo
c) Shortwave
Shortwave
Rise in temperature of a surface is proportional to its specific heat
a) Directly
b) Indirectly
Indirectly
Specific heat of land is…… than that of water
a) Lower
b) Same
c) Higher
Lower
Minimum temperature is reached at …
a) sunrise
b) midnight
c) 1/2 - 1 hour after dawn
1/2 - 1 hour after dawn
An air parcel is lifted till it gets saturated. The temperature attained by it is called
a) Potential temperature
b) Dew Point
c) Wet bulb
Dew Point
Cloudy nights are……….
a) cold
b) normal
c) warm
warm
Water vapour is transparent to terrestrial radiation
a) completely
b) partially
C) indifferent
partially
Higher the temperature….. would be the wavelength of emitted radiation
a) longer
b) shorter
shorter
Air is a bad conductor of heat. A parcel of air can therefore be regarded as insulated from the environment
a) False
b) True
True
Warmer the earth.. will be the Nocturnal radiation
a) larger
b) smaller
Or
a) weaker
b) moderate
c) intense
larger/intense
Heat is the……. of the KE of all molecules and atoms of a substance
a) sum total
b) average
sum total
The solar radiation consists of about 46 %
a) UV
b) IR
c) Visible
IR
The total energy radiated by a black body is proportional to its temperature (T)
a) T power two
b) T power three
c) T power four
T power four
Intense radiation are emitted by
a) Hot bodies
b) Cold bodies
c) Stars
Hot bodies
The wavelength of most intense radiation is inversely proportional to its……..
a) Absolute temperature
b) Humidity
c) Albedo
Absolute temperature
Hot bodies (like sun) radiate
a) Short Waves
b) Long Waves
c) Both
Short Waves
The flow of heat from earth surface is 77% by
a) Sensible Heat
b) Latent Heat
Latent Heat
-40° C = -40° F
a) True
b) False
True
Surface Temperature is recorded at a height of ……..
above ground
a) 1.5 m
b) 1.25m
c) 2 m
1.25m or 4 feet
The door of Stevenson’s screen should open
a) opposite to sun
b) into sun
c) any direction
opposite to sun
The liquid used in Minimum Thermometer is
A) mercury
B) alcohol
c) sprit
alcohol
Freezing point of water is
a) 0° F
b) 12° F
C) 22° F
d) 32°F
32°F
Boiling point of water is
a) 100° F
b) 112° F
c) 212° F
d) 312° F
212° F
Freezing point of water is
a) 173° K
b) 273°K
c) 373° K
d) 473° K
273°K
Boiling point of water is
a) 373°K
b) 273° K
C) 173° K
d) 312° K
373°K
Convert 68° F into Kelvin temperature
a) 233° K
B) 283° K
C) 294° K
d) 293°K
293°K
K= C+273
9C/5=F-32
Diurnal variation of temperature is least on a day when it is
a) Clear
b) Partly cloudy
c) Cloudy
d) Overcast
Overcast
A clear and calm night is cooler than a cloudy night, because nocturnal radiation
A) escape through cloud
b) are partly radiated back by clouds to earth
C) are fully absorbed by H2O
D) are fully prevented by clouds to escape
are partly radiated back by clouds to earth
- AIR DENSITY
Density is ……at poles than equator
a) Higher
b) Lower
c) Same
Above 8 km density is …….. at poles than at equator
a) Higher
b）Lower
c)Same
The altitude in ISA at which air density is the same as the observed density is called
a) Density Altitude
b) ISA Density
c) Real Density
Density is usually expressed as
a) Kg/sq m
b) g/cu m
c) N/sq m
Higher density altitude means …. density
a) Higher
b) Lower
c) Same
For given pressure and temperature moist air has density
a) Higher
b) Lower
c) Same
Air is less denser in
a) High Altitudes
b) Warm Air
c) High humidity
d) All these
Density altitude may be defined as:
a) The altitude in a standard atmosphere at which the prevailing pressure occurs.
b) The altitude in a standard atmosphere at which the prevailing density occurs.
c) Surface of constant atmospheric pressure related to standard atmosphere of 1013.2 hPa
If pressure increases the density altitude
a) Increases
B) Lowers
C) Remains the same
For every 1°C change in temperature, density altitude differs by
a) 33 ft
b) 100 ft
C) 120 ft
D) 210 ft
- HUMIDITY
The ratio in % between the amount of water vapour present in the air to the amount of water vapour that it can hold at the same temperature is
a) Humidity
b) Relative humidity
c) Dew point
The temperature to which air be cooled at constant pressure to become saturated, is called
a) Wet bulb temperature
b) Dry bulb temperature
c) Dew point
d) Humidity
Free air temperature, Wet bulb temperature and Dew point temperature are equal when
a) Air temperature is 0°C
b) Relative humidity is 100%
c) Air temperature is not below 0°C
On a rainy day compared to sunny day the length of runway required is
a) More
b) Less
c) Same
The spread (difference) between Free air temperature and Dew point temperature is …. when air is saturated
a) Large
b) Least
c) Same
The saturation vapour pressure over water is .. .. than the ice
a) More
b) Less
c) Same
As the temperature of the air increases, the amount of water vapour required to saturate it ……..
a) decreases
b) increases
c) remains same
The actual amount of water vapour contained in a given volume of air at a given temperature is termed as …
a) Relative Humidity
b) Specific Humidity
c) Absolute Humidity
Humidity Mixing Ratio ….. when air is lifted adiabatically
a) decreases
b) remains constant
C) increases
- WIND
In S hemisphere if an observer faces wind, low will be to his
a) Right
b) Left
In N hemisphere due to rotation of earth winds are deflected to
a) Left
b) Right
Local Winds follow Buys Ballot’s law
a) False
b) True
Coriolis force acts perpendicular to the ….. of wind direction in N hemisphere
a) Left
b) Right
155) Geostrophic wind is due to the balance between the forces ……….
a) Coriolis and Friction
b) Pressure gradient and Cyclostrophic
c) Pressure gradient and Coriolis
Coriolis force is strongest at ………
a) Mid latitudes
b) Poles
c) Equator
Geostrophic rule breaks down at …….
a) Mid latitudes
b) Poles
c) Equator
Fohn winds are ……. on the Leeward side of a mountain,
a) Dry & Warm
b) Cold & Humid
The wind sliding down a hill during night is called….. wind.
a) Fohn
b) Anabatic
c) Katabatic
With the onset of sea breeze there is a …… in temperature and ……. in RH.
a) Fall/Rise
b) Rise/Fall
c) Fall/Fall
Sea breeze sets in by ……. and dies off at …..
a) Night/Day
b) Day/Night
c) Both Day and Night
If an aircraft in N-hemisphere flies from H to L it will experience
a) Starboard drift
b) Port drift
In N-Hemisphere if you experience Port drift, altimeter will read
a) Under
b) Over
Lines of constant wind speed drawn on weather charts are called
a) Isobars
b) Isotachs
c) Isogons
Squall are distinguished from gusts by:
a) Shorter duration
b) Longer duration
c) Lower wind speed
The thermal wind is:
a) The wind that blows because of thermals
b) The warm wind that blows down the hill on the leeward side
c) The wind which must be added vectorially to the lower level geostrophic wind to obtain the upper level geostrophic wind
On a weather map where isobars are closely packed, the surface winds are likely to be
a) Light and parallel to isobars
b) Strong and parallel to isobars
C) strong and blowing across the lsobars
Anabatic wind occurs
a) At night
b) Any time of day and night
C) During day
Anabatic wind is stronger than katabatic
a) True
b) False
Katabatic wind is down slope cold wind due to nocturnal cooling
a) True
b) False
Katabatic wind occur due to sinking of air down the hill slope
a) True
b) False
172) Anabatic wind occur due to downward movement of air along valley
A) True
b) False
Sea breeze is stronger than land breeze
a) True
b) False
The wind blows clockwise around low in a N-hemisphere
a) True
b) False
The wind blows clockwise around low in S-hemisphere
a) True
b) False
The wind blows anticlockwise around low in N-hemisphere
a) True
b) False
The wind blows anticlockwise around low in S- hemisphere
a) True
b) False
The resultant wind that blows under the influence of pressure gradient force, geostrophic force and cyclostrophic force is called
a) Gradient wind
b) Geostrophic wind
c) cyclostrophic wind
Due to friction, from day to night for an isobaric pattern (in N hemisphere) the Surface wind backs and weakens
a) True
b) False
The winds which spiral inward in a counter-clockwise direction in the N Hemisphere are associated with
a) Turbulence
b) High pressure area
c) Low pressure area
Lower level wind 05010 kt, upper level wind 23005 kt, what is the thermal wind
a) 05005 kt
b) 23015 kt
c) 05015 kt
A change in wind direction from 310° to 020° is
a) Backing
b) Veering
A change from 270° to 250° is
a) Backing
b) Veering
Sudden change in wind speed from 10 kt to 30 kt and then to 15 kt is
a) Gust
b) Squall
c) gale
Sudden change in wind speed from 10 kt to 30 kt for 2 - 3 minutes
a) Squall
b) Gust
A significant wind shear can be associated with TS or line squall
a) False
b) True
Cyclostrophic wind gives a good approximation of the 2000’ wind in an intense tropical storm
A) True
B) False
Rotor clouds have extremely turbulent flying conditions
a) False
b) True
Friction causes winds to flow cross isobaric by …….
over land and …… over sea
a) 20°/10°
b) 20º/30°
c) 40°/30°
If the S is warmer than N, level by level, from surface up to higher levels, then the …….wind will strengthen with height with no change in direction in N hemisphere
a) Ely
b) Wly
c) Sly
d) Nly
Gradient wind is ……of geostrophic wind in an anticyclone
a) Under estimate
b) Accurate
c) Over estimate
Gale is
a) persistent strong winds with mean speed 44 kt, associated with thunderstorm
b) marked increase in wind speed lasing few minutes associated with CB or DS (dust storm)
c) persistent strong winds exceeding 33 kit, associated with depression
In N hemisphere thermal wind is parallel to …… with low value to left
a) Isobars
b) Isotherms
c) Isallobars
The inertial flow is
a) cyclonic in both the Hemispheres
b) anticyclonic in both the Hemispheres
c) anticyclonic around an anticyclone
Upper level wind is 24025 kt, lower level wind is 16015 kt, the thermal wind is?
a) 16010 kt
b）24040 kt
c) 24010 kt
- VISIBILITY AND FOG
Fog is reported when visibility is reduced to
a) Less than 1000 m
b) 1000m
c) 1000 to 2000
RVR is reported when visibility falls below
a) 500 m
b) 1000 m
с) 1500 m
Radiation fog occurs
a) Over land
b) Over sea
c) During day
When visibility reduces between 5000 m and 1000 m and RH is almost 100%, it is
a) Mist
b) Haze
c) Fog
Radiation Fog forms over N India during
a) May to June
b) Dec to Feb
d) Oct to Nov
Warm and moist air moving over a cold ground gives rise to:
a) Thunder clouds
b) Fog and stratus
c) Frontal clouds
Warm and moist air moving over a cold surface causes
a) Radiation Fog
b) Advection Fog
c) Frontal Fog
The radiation fog forms due to
a) Heating of the earth during day
b) Radiational cooling of earth at night
c) Advection of cold air
The radiation fog activity increases after the passage of a ……….
a) WD
b) Depression
c) Col
Radiation fog is essentially a ………… phenomena
a) Nocturnal
b) Dusk
c) Day
The radiation fog forms over ……
a) Water
b) Land
c) Both
The ……. fog forms due to horizontal movement of warm moist air over cold surface
a) Radiation
b) Advection
c) Frontal
Advection fog forms during
a) night only
b) day time only
c) any time of day and night
For formation of Radiation fog
a) There should be sufficient moisture in atmosphere, cloudy sky, nil wind
b) There should be sufficient moisture in atmosphere, clear sky, light wind.
c) There should be sufficient moisture in atmosphere, cloudy sky, strong wind
Instrument used for measuring visibility is called ….
a) Visiometer
b) Transmissometer
c) Ceilometer
Advection fog forms
a) over sea
b) over Land
c) both over land and sea
fog is …….. cloud on ground
a) stratocumulus
b) stratus
c) Nimbostratus
Frontal fog is more common with a
a) Western Disturbance
b) cyclone
c) Warm Front
d) Cold Front
The favourable pressure system for formation of fog is
a) Lows and Cols
b) High and Trough
c) Lows and Ridges
d) Highs and Cols
Thermal processes / temperature distribution which favours formation of fog is
a) Isothermal
b) Adiabatics
c) Inversion
d) SALR
- VERTICAL MOTION AND CLOUDS
Drizzle occurs from
a) CS
b) ST
c) NS
d) CU
Altostratus (AS) is
a) a) Low cloud of sheet type
b) A medium cloud of sheet type
c) A cloud of large vertical growth
d) A high cloud of sheet type
Altostratus (AS) is
a) a) Low cloud of sheet type
b) A medium cloud of sheet type
c) A cloud of large vertical growth
d) A high cloud of sheet type
Showers occurs from
a) CU
b) СВ
c) AS
d) AC
Heavy icing is possible in
a) CI
b) CS
c) ST
d) CB
To avoid icing in cloudy conditions, a pilot is advised to fly through a cloud which shows an optica phenomena
a) Halo
b) Corona
c) With multi-coloured clouds
Dark gray cloud giving continuous rain is called
a) AS
b) NS
c) ST
d) CB
A uniform layer of cloud resembling fog but not on the ground
a) AS
b) NS
c) ST
The clouds composed of ice crystals having feathery appearance
a) CI
b) CS
c) AS
Halo is associated with the cloud
a) AC
b) AS
c) CS
d) CI
NS clouds occur
a) At cold front
b) At warm front
Corona is associated with the cloud
a) AS
b) AC
с) СС
d) CS
Lenticular clouds indicate presence of
a) Warm Front
b) Cold front
c) Mountain waves
The lowest level below which condensation trails will not form is
a) Mintra Level
b) Drytra Level
c) Maxtra Level
Rain falling from cloud but not reaching ground is
a) Virgo
b) Virga
c) Mirage
CB with distinct anvil is called
a) Castellanus
b) Capillatus
c) Uncinus
Cloud ceiling is the height of the cloud covering
a) 3-4/8
b) 8/8
c) 5/8 or more
No condensation trails occur above
a) Maxtra Level
b) Dytra Level
c) Mintra Level
Cloud of operational significance has base below ..
….. m or below the highest minimum sector altitude, which is greater
a) 1500
b) 2000
c) 1000
AC cloud with cumuliform protuberances are indicative of
a) Stability
b) Instability
c) Neutrality
Hail may be experienced under the anvil of a CB
a) True
b) False
- ATMOSPHERE STABILITY AND INSTABILITY
DALR = 9.8 °C, ELR = 6.8 °C; atmosphere is
a) stable
b) unstable
c) indifferent
SALR = 5.5 °C, ELR= 4.5 °C ; atmosphere is
a) unstable
b) stable
c) indifferent
DALR > ELR > SALR
a) conditionally stable
b) latently stable
c) potentially stable
Dry air is unstable when
a) ELR=DALR
b) ELR>DALR
c) ELR<DALR
The saturated air is said to be unstable if
a) SALR=ELR
b) SALR<ELR
c) SALR > ELR
If ELR = SALR = DALR the atmosphere is
a) Stable
b) Instable
c) Indifferent
DALR means:
a) The rate at which temperature of unsaturated parcel of air falls with height when made to ascend adiabatically.
b) The rate at which temp falls with height.
c) The rate at which ascending parcel of saturated air cools.
Surface temp, is 30° C. Assuming DALR. what is the temperature at 2 km
a) 18° C
b) 10° C
c) 42° C
An Isothermal atmosphere is
a) Stable
b) Unstable
c) Neutral
If environmental lapse rate(ELR) is less than SALR, the atmosphere is said to be:
a) Absolutely unstable
b) Conditionally stable
c) Absolutely stable
DALR is approximately
a) 5°C/km
b) 15 ° C/km
с) 10 °C/km
SALR at mean sea level is about
a) 10 °C/Km
b) 5 °C/Km
c) 5° F/Km
SALR approaches DALR
a) at 0°C
b) at -15°F
c) at-40°C
Dry air having a temperature of 35°C on surface when forced to rise adiabatically by 1 km would attain a temperature of
a) 29°C
b) 25°C
c) 45°C
Inversion in the atmosphere indicates
a) Stability
b) Instability
c) Neutrality
Inversion is … Lapse Rate (LR)
a) Positive
b) Negative
c) Neutral
Environmental LR can be more than DALR
a) True
b) False
The process which to a large extent determines the vertical distribution of temperature in atmosphere is
a) Adiabatic
b) Isothermal
c) Isentropic
Rise in temperature with height is
a) Inversion
b) Lapse
c) Normal
Inversion is common in
a) Post Monsoon
b) Monsoon
c) Winters
- OPTICAL PHENOMENA
Aurora Australis occur in the
a) S hemisphere
b) N hemisphere
c) Equator
Aurora Australis called …. Lights
a) Northern
b) Southern
c) Temperate
Aurora Borealis occur in the
a) S hemisphere
b) N hemisphere
c) Equator
Aurora Borealis are called….. Lights
a) Northern
b) Southern
c) Temperate
Corona occur in….. clouds
a) AS
b) NS
c) CS
Bishop’s ring is due to the diffraction of light by fine particles of
a) water
b) dust
c) ice
The radius of the Bishop’s ring is about
a) 32°
b) 22°
с) 42°
Superior Mirage occurs in marked
a) Lapse
b) Isothermal
c) Inversion
Inferior Mirage occurs when there is
a) Lapse
b) Isothermal
c) Inversion
Corona are formed due to the ….. of light
a) Refraction
b) Diffraction
c) Scattering
Corona are formed due to light, passing through
a) Mist only
b) Fog only
c) small water or ice particles only
d) Any one of all these
Halo is produced by
a) Refraction
b) Diffraction
c) Scattering
Halo is produced when light passes through
a) water particles
b) ice crystals
c) both
Halo occur in the cloud
a) AS
b) NS
c) CS
Halo is luminous ring of ….. radius
a) 32°
b) 22°
с) 42°
Halo round the sun shows a pure clear ….. on the outside
a) Red
b) Yellow
c) Violet
Halo signifies predominance in the cloud of
a) Supercooled water drops
b) Ice crystals
c) Both
The cloud which cause Halo has … chances of ice accretion
a) negligible
b) maximum
c) medium
Sometimes a halo with a radius of ………. is observed, called Large Halo
a) 32°
b) 42°
с) 22°
Halo occurs from… cloud
a) Low
b) Medium
c) High
- PRECIPITATION
When super cooled water drops and ice particles co-exist, the ice crystals grow at the expense of the water drops because
a) Saturation vapour pressure over water drops is less than over the ice crystals
b) Saturation vapour pressure over the ice crystals is less than over water drops
c) The ice crystals convert into water drops
The clouds whose tops extend well above the freezing level are called
a) Warm Clouds
b) Cold Clouds
c) Moderate Clouds
The clouds whose tops do not extend to the freezing level are called
a) Warm Clouds
b) Cold Clouds
c) Moderate Clouds
Coalescence Theory explains occurrence of rainfall from the
a) Warm Clouds
b) Cold Clouds
c) Both types of Clouds
Ice crystal Theory explains occurrence of rainfall from the
a) Warm Clouds
b) Cold Clouds
c) Both types of Clouds
Giant Nucleus Theory explains occurrence of rainfall over
a) Maritime areas
b) Inland areas
c) Hilly areas
Very heavy precipitation as showers over a short period is called
a) Flash floods
b) Cloud Burst
c) Orographic Rain
Rain shadow area is on the…. . of the mountain range
a) Top
b) Windward side
c) Leeward side
Sleet is a mixture of
a) Hall & Snow
b) Rain & Snow
c) Frozen Rain
Rainfall in the tropics is more in
a) Winters
b) Summers
c) Post monsoon
Rainfall in the tropics is more in the
a) Morning
b) Afternoon
c) Night
Rainfall in the temperate latitudes is more in
a) Winters
b) Summers
c) Spring
Over J&K and western Himalayas Rainfall is more in
a) Winters
b) Summers
c) Post monsoon
Rainfall over coastal areas is more in the
a) Evening
b) Afternoon
c) Night & early morning
Areas to the ….. of western Ghats of India are rain shadow areas
a) W
b) S
c) E
A sudden rise in the level of rivers or streams causing floods is called
a) Cloud Burst
b) Catchments flooding
c) Flash Floods
Artificial rain making is also termed as
a) Simulation
b) Cloud seeding
c) Nucleation
Fog can be dispersed for a short period by artificial stimulation
a) True
b) False
Showery precipitation occurs from
a) NS
b) AC
с) СВ
A day is called Rainy day when rainfall in 24 hr is .…… mm or more
a) 1.5
b) 2
c) 2.5
- ICE ACCRETION
Hoar frost occurs on airframe in clear air when the temperature of airframe is
a) below the frost point
b) frost point
c) just above the frost point
In clouds at temperatures below 0° C an aircraft may encounter icing of the type
a) only Glazed
b) only Rime
c) intermediate between these two
Opaque Rime ice is
a) Light porous
b) Solid
c) Mixture of porous and solid
Rime is formed by freezing of …..supercooled water droplets on airframe when aircraft is flying through
clouds
a) Small
b) Large
c) Medium
Glazed ice is formed by freezing of ….. .. supercooled water droplets on airrame when aircraft is flying through clouds
a) small
b) Large
c) medium
The …… ice poses serious aviation hazard
a) Rime
b) Hoar Frost
c) Glazed
Airframe icing occurs below 0°C. Its probability of occurrence decreases progressively below -20 °C, as at lower temperatures the proportion of super-cooled water drops in a cloud
a) Increases
b) Decreases
c) Does not change
CI, CS and CC clouds consist mostly ice crystals. Icing hazard is therefore
a) Maximum
b) Medium
c) Negligible
AS, NS consist of supercooled water drops and ice crystals in varying proportion .…… icing is possible.
a) Maximum
b) Light or moderate
c) Negligible
In AC clouds ….. icing is likely in mountainous areas
a) Severe
b) Light to moderate
c) Negligible
In TCU icing may range from light to severe type at least up to ………. level.
a) - 40 °C level
b) 30 °C level
c) - 20 °C level
In CB icing may range from light to severe type up to -20°C level. Below this temperature severe icing is
a) not significant
b) significant
c) maximum
Liquid water content is an important factor in icing. As the maximum water concentration is around ..……. maximum ice formation in clouds may also be expected around that level.
a) -25° C level
b) -20° C level
c) -15° C level
Carburetor icing occurs when air from intake passes through a venturi (choke) and causes expansional cooling and vaporization of fuel. Serious icing can occur at extreme temperatures
a) 13 °C
b) 30°C to -10°C
c) 20 °C
…….. occurs in a moist cloudless air on an aircraft surface having temp. below 0° C, due to sublimation of water vapour onto feathery ice crystals.
a) Rime
b) Glazed
c) Hoar Frost
..……. occurs in St, Sc, Ac, Cu, Ns at temperature -10 to -40° C and in Cb at temperature -20 to -40°C
a) Rime
b) Glazed
c) Hoar Frost
In clouds .…… occurs when a wide range of water drop sizes are present at temperatures between 0°C and -40°C
a) Rime
b) Glazed
c) Mixture of rime and clear ice
…….. occurs in AS, NS, SC and towering CU or CB between 0° C and -20° C, in warm front below 0° C, especially if the aircraft has rapidly descended from a colder region
a)Glazed
b) Fume
c) Mixture of Rime and Clear ice
When fog freezes on parked aircraft it produces..,
a) Hoar Frost
b) Hoar Frost
c) Clear ice
Icing ……. the stalling speed appreciably
a) Decreases
b) Increases
c) Does not increase/decrease
- THUNDERSTORM
The condition necessary for the formation of a thunderstorm are:
a) Steep lapse rate, strong winds
b) shallow lapse rate, adequate supply of moisture
c) Steps lapse rate , adequate supply of moisture and trigger action.
Hail is most likely to fall from a cloud
a) Having layers
b) Composed of Ice crystals
c) Having strong vertical development
Norwesters are
a) The western disturbances which affect NW India
b) Severe thunderstorms which occur over NE India during hot weather period
c) Severe thunderstorms which occur over Peninsula during hot weather period
Dust Storm usually occurs over NW India during
a) Post-monsoon
b) Winter
c) Pre-Monsoon
A ‘mature’ thunderstorm has
a) updraft only
b) downdraft only
C) updrafts and downdrafts
Aircraft icing is most favoured in the cloud which have temperatures ranging between
a) - 20° C and - 40° C
b) 0° C and - 20° C
c) below -40 ° C
A short duration, showery precipitation is associated with
a) ST
b) AS
c) CB
Hail is
a) Solid precipitation which commonly occurs over the mountainous regions in winter.
b) Frozen or partly frozen rain falling from sheet type of clouds
c) Solid precipitation falling from a deep convective cloud
The most hazardous cloud for aviation is
а) СВ
b) CU
c) NS
The life of a Cb cell is usually
a) 7 to 8 hrs
b) 3 to 4 hrs
c) 2-3 hr
Generally the severest activity of a, heat type, TS is for
a) 2 hrs
b) 30 to 45 min
c) 3 to 4 hr
Norwesters occur during
a) Jan-Feb
b) Mar-May
c) June-Sep
d) Oct - Dec
Norwesters occur during
a) Winter
b) Hot weather
c) Monsoon
d) Post Monsoon
Norwesters affect
a) N India
b) Bengal, Bihar, Orissa and Assam
c) Central India
The trigger action may take place due ro
a) Clear night sky no wind
b) Orographic lifting
c) high pressure
Norwesters normally occur during
a) Mornings
b) Afternoons
c) Nights
Norwesters originates over
a) Chota - Nagpur hills
b) Deccan Plato
c) Khasi hills
Andhi (blinding storms) occur generally over
a) S India
b) N India
c) NE India
Wind speed in Light DS is
a) 25 kr
b) 30 kt
c) up to 21 kt
The diameter of Microburst is
a) less than 4 km
b) less than 2 km
c) less than 6 km
The diameter of and Macroburst
a) < 4 km
b) 4 km or more
c) > 8 km
For detecting precipitation a Radar wavelength in the range .…… is suitable
a) 30 to 200 mm
b) 400-500 mm
c) 600-700 mm
For airborne radars wavelength generally used
a) 20 mm
b) 40 mm
c) 60 mm
The wavelength of TS detection X band radar is
a) 10 mm
b) 20 mm
с) 30 mm
The wavelength of storm detection S band radar is
a) 50 mm
b) 100 ram
c) 200 mm
Over plains TS mostly occur during the
a) afternoon
b) night
c) early morning
Over valley and foot hills TS generally occur during
a) afternoon
b) night & early morning
Over the sea TS are more frequent
a) afternoon
b) night
c) early morning
The life of Mesoscale Convective Complex TS is
a) 2-3 hr
b) 3-4 hr
c) 6 to 24 hr
Loud peals of thunder, frequent flashes of lightning, moderate or heavy showers accompanied by light hail with maximum wind speed 15-40 kt is classified as
a) Light TS
b) Moderate TS
c) Severe TS
For a severe TS one of the requirements is strong wind shear
a) Horizontal
B) Vertical
c) Slant
Severe TS cells are tilted
a) in vertical
b) to the South
c) to the North
When flying through on active TS, lightning strikes are mostly likely
A) Above 5000 ft and under the anvil
B) In the clear air below the cloud in rain
C) In the temperature band between +10 C and -10 C
D) At or above 10000 ft
Hazards of the mature stage of TS Cell include lighting, turbulence and
A) Microburst, wind-shear and anvil
b) Icing, microburst and WS
c) Icing, drizzle and microburst
D) WS, hail and fog
Hail grows by
a) freezing as it leaves the cloud
b) up and down forces in CU cloud
c) collision with ice crystals
D) collision with supercooled water drops
- AIR MASSES, FRONTS AND WESTERN DISTURBANCES
Airmass which originates at sea in High latitudes is called
a) Polar maritime
b) Tropical continental
c) Tropical maritime
The air mass which originates over equatorial region is
a) Warm & dry
b) Warm & Moist
c) Cold & dry
If the advancing cold front is colder than the cool air mass of the warm front, the advancing cold front undercuts and lifts both the warm and cool air masses of the warm front. This is
a) Warm Occlusion
b) Cold Occlusion
The airmass which originated over land area located in polar region:
a) Warm & dry
b) Warm & Moist
c) Cold & dry
If a warm air mass overtakes a cold air mass, it is called
a) Cold Front
b) Warm Front
c) Occluded Front
At warm front
a) Warm air overtakes the cold air
b) Cold air undercuts the warm air
The conditions are always unstable at
a) Cold front
b) Warm front
Line squall occurs about 100-300 km ahead of
a) Warm front
b) Cold front
Precipitation occurs over a belt of 30 - 50 km on both side of front
a) Cold front
b) Warm front
Cold front moves at …… the speed of a warm front moves
a) Same
b) Double
c) Half
Line Squalls occur …. .. of Cold front
a) Ahead
b) Behind
c) At the
Fronts are associated with
a) Tropical cyclone
b) Monsoon Depression
c) Extratropical Cyclones
CB, Roll-type clouds, SC, AC with embedded CB are associated
a) Cold front
b) Warm front
The Surface of discontinuity between the Polar Easterlies and the temperate Westerlies is called
a) Equatorial Front
b) Tropopause
c) Polar Front
The air mass which originates from sea area located in lower Lat is
a) Warm & Dry
b) Warm & Moist
c) Cold & Moist
WDs approach India as
a) Cols
b) Occluded Fronts
c) Highs
Maximum WDs occur in
a) Summers
b) Post Monsoon
c) Winters
Ahead of a warm front the surface wind
a) Backs & weakens
b) Veers & strengthens
c) Backs & strengthens
On approach of a Warm Front temperature
a) Fall
b) Rise
c) Remain same
CI, CS, AS, NS, ST in sequence are associated with the front
a) Warm
b) Cold
c) Occluded
During the passage of a Cold Front winds
a) Suddenly become squally
b) Back and weaken
c) Veer and are of moderate strength
Visibility is poor in a Warm Front
a) Ahead
b) Ahead & During
c) After & During
Fog occurs in Cold Front
a) Ahead
b) During
c) After
WD is a.……. front
a) Cold
b) Warm
c) Occluded
FZRA and FZFG occur …. … of a warm front
a) Ahead
b) During
c) After
Precipitation ceases after the passage of a front
a) Cold
b) Warm
c) Occluded
During the approach of a Warm Front wind
a) Backs
b) Veers
c) Does not change
A WD has two or more closed isobars, at 2 hPa interval, it is termed as
a) Troughs in Westerlies
b) Western Depression
c) Western Cyclone
A WD originate over
a) Baluchistan
b) Caspian sea
c) Mediterranean, Caspian and Black Seas
Induced lows develop to the ..….. of a WD
a) N
b) S
c) NE
- JET STREAMS
The arbitrary lower limit of jet core velocity has been assigned by WMO as
a) 60 kt
b) 60 m/s
c) 70 m/s
Jet stream has
a) one maxima
b) one or more maxima
c) only two maxima
The vertical wind shear in a Jet stream is about
a) 5m/s/ km
b) 6m/s/km
c) 8m/s/km
Compared to horizontal wind shear the vertical wind shear in a Jet stream is
a) weaker
b) stronger
c) same
In a jet stream, the path of the maximum speed is known as
a) Core
b) Axis
c) Jet streak
The wind speed along the axis of a jet stream is always
a) Uniform
b) Not uniform
Along the axis of a jet stream there are centres of high speed winds, these are called
a) Jet streaks
b) Core
c) Axis
In a wavy jet the Jet streaks are located over or near the
a) Ridge
b) Trough
c) Between Trough and Ridge
Sub-tropical Jet Stream (STJ) is
a) Westerly
b) Easterly
c) Southerly
The normal position of Sub-tropical Jet Stream is
a) 30° N
b) 27° N
c) 35° N
The southern most position of STJ is in February is
a) 22° N
b) 20° N
c) 18° N
The STJ affects India from
a) Jun to Jul
b) Oct to May
c) Aug to Sep
397) STJ has a layered structure. There are often two layers of maximum wind to the ….. of jet core
a) S
b) N
c) SW
The STJ strengthens
a) Northwards
b) Upstream
c) Downstream
At and near the STJ the temperature gradient is very
a) Small
b) Large
c) Moderate
Vertical wind shear in STJ is greater ……….. the core
a) above
b) below
c) along
The TJ prevails over the Indian Peninsula from
a) May to Jun
b) Sep to Oct
c) Jun to Aug
The TJ is located over the Indian Peninsula, approximately at
a) 13° N
b) 17° N
c) 18° N
The TJ is located over Indian, approximately at a height of
a) 15-16 km
b) 12 - 13 km
c) 11 - 12 km
The TJ is strongest in
a) July-Aug
b) Sep-Oct
c) June
In the TJ the wind shears are much …… than the STJ
a) more
b) less
c) same
TJ is
a) Westerly
b) Easterly
c) Southerly
A jet Stream can be recognized by
a) High level dust
b) High Pressure
c) Streaks of Cl
d) Lenticular clouds
Flying at right angles to a jet stream with falling pressure you will experience
a) wind from left
b) Increasing head wind
c) Increasing tail wind
d) Wind from right
When and Where tropical jet stream occurs
A) All year along equator
B) In middle East in summers
C) In winters over Russia
d) In summers over SE Asia and Central Africa
- MOUNTAIN WAVES
For mountain waves to form there should be flow of air across the ridge, generally within ……….of the perpendicular to the ridge.
a) 30°
b) 45°
c) 60°
For mountain waves to form the wind speed for small mountains should be atleast
a) 15 m/s
b) 10 m/s
c) 7m/s
For mountain waves to form the wind speed for large mountains should be atleast
a) 15 m/s
b) 10 m/s
c) 7m/s
For mountain waves to form the atmosphere should be …..….. up to the ridge, where air stream strikes the ridge.
a) Unstable
b) Stable
c) Indifferent
For mountain waves to form the atmosphere should be …… at higher levels above the ridge
a) Unstable
b) Stable
c) Indifferent
In Mountain waves the Rotor clouds form in
a) Troughs
b) Ridges
c) Valley
Clear air turbulence is often encountered
a) At the boundary of a jet stream
b) In the wake of a passing airplane
c) In the wake of a larger airplane at take off and landing
d) All of the above
Most CAT occurs on the ……of a jet stream and in the vicinity of upper level frontal zones where temperature contrasts are strong.
a) Fringes
b) Within the core
c) Axis
Most CAT occurs on the ……of a jet stream and in the vicinity of upper level frontal zones where temperature contrasts are strong.
a) Fringes
b) Within the core
c) Axis
CAT is the bumpiness experienced by aircraft at high altitudes…….. in either cloud-free conditions or in stratiform clouds
a) above 18,000 feet
b) below 18,000 feet
c) below 28,000 feet
When approaching an area where mountain waves have been reported, a pilot should expect:
a) Possible presence of roll clouds and lenticular clouds
b) Intense updrafts and downdrafts on the lee side of the mountains
c) Moderate to severe turbulence as far as 20 to 30 miles from the range on lee side
D) all of the above
- TROPICAL SYSTEMS
Wind speed in a tropical severe cyclone is:
a) 27-33 kt
b) 48 - 63 kt
c) 17-27 kt
