Vayudoot Aviation

1. The most hazardous cloud for variation is

CU

CB

NS

2. The diametre of and Macroburst

4 km or more

› 8 km

‹ 4 km

3. Hail grows by

freezing as it leaves the cloud

up and down forces in CU cloud

collision with supercooled water drops

collision with ice crystals

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

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

At or about 10000 ft

Above 5000 ft and under the anvil

In the clear air below the cloud in rain

5. The trigger action may take place due to

Orographic lifting

Clear night sky, no wind

high pressure

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

Slant

Horizontal

Vertical

7. Duststorm usually occurs over NW India during

Post-monsoon

Winter

Pre-Monsoon

8. Norwesters originates over

Khasi hills

Deccan Plato

Chota-Nagpur hills

9. The life of Mesoscale Convective Complex TS is

3-4 hr

2-3 hr

6 to 24 hr

10. The life of a Cb cell is usually

3 to 4 hrs

2 -3 hr

7 to 8 hrs

11. The wavelength of storm detection S band radar is

100 mm

50 mm

200 mm

12. Norwesters occur during

Monsoon

Winter

Post-Monsoon

Hot weather

13. Andhi (blinding storms) occur generally over

S India

N India

NE India

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

600 - 700 mm

400 - 500 mm

30 to 200 mm

15. Norwesters normally occur during

Mornings

Afternoons

Nights

16. 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

Moderate TS

Light TS

Severe TS

17. Severe TS cells are tilted

in vertical

to the south

to the North

18. Norwesters occur during

Jan-Feb

Mar-May

Oct-Dec

June-Sep

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

Icing, drizzle and microburst

WS, hail and fog

Icing, microburst and WS

Microburst, wind-shear and anvil

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

2 hrs

3 to 4 hr

30 to 45 min

21. Hail is most likely to fall from a cloud

Composed of Ice crystals

Having strong vertical development

Having layers

22. Andhi (blinding storms) occur generally over

N India

NE India

S India

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

Steep lapse rate, adequate supply of moisture and trigger action

Steep lapse rate, strong winds

Shallow lapse rate, adequate supply of moisture

24. Hail is

Frozen or partly frozen rain falling from sheet type of clouds

Solid precipitation commonly occurring over the mountainous regions in the winters

Solid precipitation falling from a deep convective cloud

25. Wind speed in Light DS is

up to 21 kt

30 kt

25 kt

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

-20°C and -40°C

0°C and -20°C

below -40°C

27. For airborne radars wavelength generally used

20 mm

60 mm

40 mm

28. Over plains TS mostly occur during the

afternoon

early morning

night

29. A 'mature' thunderstorm has strong

updrafts and downdrafts

downdraft only

updraft only

30. Norwesters affect

Bengal, Bihar, Orissa and Assam

N India

Central India

31. Over the sea TS are more frequent

afternoon

night

early morning

32. The diameter of Microburst is

less than 4 km

less than 2 km

less than 6 km

33. Norwesters are

Sever thunderstorms which occur over Peninsula during hot weather period

The western disturbances which affect NW India

Severe thunderstorms which occur over NE India during hot weather period

34. Over valley and foot hills TS generally occur during

afternoon

night & early morning

35. The wavelength of TS detection X band radar is

20 mm

30 mm

10 mm

36. A short duration, showery precipitation is associated with

ST

AS

CB

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