Vayudoot Aviation

1. Over plains TS mostly occur during the

early morning

night

afternoon

2. Hail is most likely to fall from a cloud

Having strong vertical development

Having layers

Composed of Ice crystals

3. The life of Mesoscale Convective Complex TS is

6 to 24 hr

2-3 hr

3-4 hr

4. For airborne radars wavelength generally used

20 mm

40 mm

60 mm

5. Loud peals of thunder, frequent flashes of lightning, moderate or heavy showers accompanies by the light hail with maximum wind speed 15-40 kt is classified as

Light TS

Moderate TS

Severe TS

6. Hail is

Solid precipitation falling from a deep convective cloud

Frozen or partly frozen rain falling from sheet type of clouds

Solid precipitation commonly occurring over the mountainous regions in the winters

7. Andhi (blinding storms) occur generally over

S India

N India

NE India

8. The condition necessary for the formation of a thunderstorm are

Steep lapse rate, strong winds

Steep lapse rate, adequate supply of moisture and trigger action

Shallow lapse rate, adequate supply of moisture

9. Hail grows by

collision with ice crystals

freezing as it leaves the cloud

up and down forces in CU cloud

collision with supercooled water drops

10. Norwesters affect

Bengal, Bihar, Orissa and Assam

Central India

N India

11. Norwesters occur during

Hot weather

Post-Monsoon

Monsoon

Winter

12. Norwesters normally occur during

Mornings

Afternoons

Nights

13. Generally the severest activity of a, heat type, TS is for

3 to 4 hr

30 to 45 min

2 hrs

14. The wavelength of TS detection X band radar is

30 mm

20 mm

10 mm

15. The diametre of and Macroburst

‹ 4 km

› 8 km

4 km or more

16. The wavelength of storm detection S band radar is

200 mm

100 mm

50 mm

17. Hazards of the mature stage of a TS cell include lighting, turbulence and

Icing, drizzle and microburst

Icing, microburst and WS

Microburst, wind-shear and anvil

WS, hail and fog

18. The life of a Cb cell is usually

7 to 8 hrs

2 -3 hr

3 to 4 hrs

19. The most hazardous cloud for variation is

CB

CU

NS

20. Over the sea TS are more frequent

night

afternoon

early morning

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

600 - 700 mm

400 - 500 mm

30 to 200 mm

22. The diameter of Microburst is

less than 4 km

less than 6 km

less than 2 km

23. Aircraft icing is most favoured in the cloud which have temperatures ranging between

below -40°C

0°C and -20°C

-20°C and -40°C

24. For a severe TS one of the requirements is strong Wind Shear

Slant

Horizontal

Vertical

25. The trigger action may take place due to

high pressure

Clear night sky, no wind

Orographic lifting

26. Severe TS cells are tilted

in vertical

to the North

to the south

27. Over valley and foot hills TS generally occur during

afternoon

night & early morning

28. Norwesters occur during

June-Sep

Mar-May

Jan-Feb

Oct-Dec

29. A short duration, showery precipitation is associated with

AS

CB

ST

30. A 'mature' thunderstorm has strong

updraft only

downdraft only

updrafts and downdrafts

31. Norwesters are

The western disturbances which affect NW India

Severe thunderstorms which occur over NE India during hot weather period

Sever thunderstorms which occur over Peninsula during hot weather period

32. Wind speed in Light DS is

up to 21 kt

25 kt

30 kt

33. Duststorm usually occurs over NW India during

Post-monsoon

Pre-Monsoon

Winter

34. Norwesters originates over

Deccan Plato

Chota-Nagpur hills

Khasi hills

35. When flying through on active TS, lighting strikes are most likely

In the clear air below the cloud in rain

Above 5000 ft and under the anvil

In the temperature band between +10° and -10°C

At or about 10000 ft

36. Andhi (blinding storms) occur generally over

N India

NE India

S India

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