Thunderstorm

1.       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.

2.       Hail is most likely to fall from a cloud

a.      Having layers

b.      Composed of Ice crystals

c.    Having strong vertical development

3.       Nor westers are

a.      The western disturbances which affect NW India

b.    Severe thunderstorms which occur over NE India during hot weather periot

c.      Severe thunderstorms which occur over Peninsula during hot weather perioc

4.       Duststorm usually occurs over NW India during

a.      Post-monsoon

b.      Winter

c.    Pre-Monsoon

5.       A 'mature' thunderstorm has

a.      A strong updraft only

b.      Strong downdraft only

c.    Strong updrafts and downdrafts

6.       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

7.       A short duration, showery precipitation is associated with

a.      ST

b.      AS

c.    CB

8.       Hail is

a.      Solid precipitation which commonly occurs over the mountainous regions during winter.

b.      Frozen or partly frozen rain falling from sheet type of clouds

c.    Solid precipitation falling from a deep convective cloud

9.       The most hazardous cloud for aviation is

a.    CB

b.      CU

c.      NS

10.   The life of a Cb cell is usually

a.      7 to 8 hrs

b.      3 to 4 hrs

c.    1/2 - 1 hr

11.   Generally the severest activity of a CB clouds is for

a.      2 hrs

b.    30 to 45 min

c.      3 to 4 hr

12.   Norwesters occur during

a.      Jan-Feb

b.    Mar-May

c.      June-Sep

d.      Oct - Dec

13.   Norwesters occur during

a.      Winter

b.    Hot weather

c.      Monsoon

d.      Post Monsoon

14.   Norwesters affect

a.      N India

b.    Bengal, Bihar, Orissa and Assam

c.      Central India

15.   The trigger action may take place due ro

a.      Clear night sky no wind

b.    Orographic lifting

c.      Divergence due to high pressure

16.   Norwesters normally occur during

a.      Mornings

b.    Afternoons

c.      Nights

17.   Norwesters originates over

a.    Chota-Nagpur hills

b.      Deccan Plato

c.      Khasi hills

18.   Andhi (blinding storms) occur generally over

a.      S India

b.    N India

c.      NE India

19.   Wind speed in Light DS is

a.      25 kr

b.      30 kt

c.    up to 21 kt

20.   The diametre of Microburst is

a.    less than 4 km

b.      less than 2 km

c.      less than 6 km

21.   The diametre of and Macroburst

a.      < 4 km

b.    4 km or more

c.      > 8 km

22.   For detecting precipitation a Radar wavelength in the range ... is suitable

a.    30 to 200 mm

b.      400-500 mm

c.      600-700 mm

23.   For airborne radars wavelength generally used

a.      20 mm

b.      40 mm

c.    60 mm

24.   The wavelength of TS detection X band radar is

a.      10 mm

b.      20 mm

c.    30 mm

25.   The wavelength of storm detection S band radar is

a.      50 mm

b.    100 ram

c.      200 mm

26.   Over plains TS mostly occur during the

a.    afternoon

b.      night

c.      early morning

27.   Over valley and foot hills TS generally occur during

a.      afternoon

b.    night & early morning

28.   Over the sea TS are more frequent

a.      afternoon

b.    night

c.      early morning

29.   The life of Mesoscale Convective Complex TS is

a.      2-3 hr

b.      3-4 hr

c.    6 to 24 hr

30.   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

31.   For a severe TS one of the requirements is strong wind shear

a.      Horizontal

b.    Vertical

c.      Slant

32.   Severe TS cells are tilted

a.    in vertical

b.      to the South

c.      to the North