THUNDERSTORMS – Air – DGCA Question Bank For Politics

#1. What is the approximate maximum diameter of a microburst?

20 km

50 km

4 km

400 m

#2. Which of the following causes echoes on meteorological radar screens?

Water vapour

Fog

Any cloud

Hail

#3. What are the requirements for the formation of a thunderstorm?

A stratocumulus cloud with sufficient moisture

A cumulus cloud with sufficient moisture associated with an inversion

An adequate supply of moisture, conditional instability and a lifting action

Water vapour and high pressure

#4. A microburst

occurs only in tropical areas

has a diameter up to 4 km

is always associated with thunderstorms

has a life time of more than 30 minutes

#5. In Central Europe when is the greatest likelihood for thunderstorms due to warm updrafts?

Late morning.

Mid - afternoon

Around midnight

Early morning.

#6. Which of the following statements describes a microburst ?

A high speed downdraft of air with a higher temperature than its surroundings

An extremely strong wind gust associated with a tropical revolving storm

A small low pressure system where the wind circulates at high speed

A high speed downburst of air with a generally lower temperature than its surroundings

#7. Which thunderstorms move forward the fastest?

Thunderstorms formed by lifting processes.

Thermal thunderstorms.

Orographic thunderstorms.

Frontal thunderstorms.

#8. In addition to a lifting action, what are two other conditions necessary for thunderstorm formation?

Stable conditions and low atmospheric pressure

Unstable conditions and low atmospheric pressure

Unstable conditions and high moisture content

Stable conditions and high moisture content

#9. Aircraft struck by lightning may sometimes get considerable damage and at least temporarily the manoeuvring of the aircraft will be made more difficult. Which one of the following statements is correct?

Aircraft made by composite material may get severe damage, the crew may be blinded and temporarily lose the hearing

An aircraft made by metal has a certain capacity to attract a lightning, but the lightning will follow the surface and therefore no damage will be caused.

An aircraft has in the atmosphere the same qualities as a “Faradays cage”, which means that struck of lightning seldom occurs. But if it happens, the result will be an occasional engine failure. The crew may get a shock.

Aircraft made by composite material can’t conduct a lightning and will therefore very seldom be struck

#10. Which thunderstorms generally develop in the afternoon in summer over land in moderate latitudes?

Airmass thunderstorms

Warm front thunderstorms

Cold mass thunderstorms

Occlusion thunderstorms

#11. How long does a typical microburst last?

1 to 2 hours.

About 30 minutes.

1 to 5 minutes.

Less than 1 minute.

#12. An airborne weather radar installation makes it possible to detect the location of

all clouds

cumulonimbus, but provided that cloud of this type is accompanied by falls of hail

stratocumulus and its vertical development

zones of precipitation, particularly liquid-state precipitation, and also their intensity

#13. Which of the statements is true concerning squall lines?

Severe squall lines always move from northwest to southeast

For severe squall lines a SIGMET is issued

Severe squall lines only occur in the tropics

For severe squall lines a TAF is issued

#14. What are the meteorological prerequisites, at low level, for thunderstorms formed by lifting processes, over land?

High air pressure (> 1013 hPa), high temperatures.

Low temperatures, low humidity.

Subsidence, inversion.

High temperatures, high humidity

#15. What is a microburst?

A small low pressure system where the wind circulates with very high speeds.

A concentrated downdraft with high speeds and a lower temperature than the surrounding air.

A concentrated downdraft with high speeds and a higher temperature than the surrounding air.

An extremely strong wind gust in a tropical revolving storm.

#16. The initial phase of a thunderstorm is characterized by

continuous up draughts

continuous downdraughts

frequent lightning

rain starting at surface

#17. In which stage of the life cycle of a single thunderstorm cell occur both up- and downdrafts simultaneously?

Cumulus stage

Dissipating stage

In all stages

Mature stage

#18. What weather condition would you expect at a squall line?

Fog

Strong whirlwinds reaching up to higher levels

Thunderstorms

Strong steady rain

#19. Thunderstorms reach their greatest intensity during the

period in which precipitation is not falling.

mature stage.

cumulus stage.

dissipating stage.

#20. A microburst phenomenon can arise in the

up draught of a cumulonimbus at the mature stage.

downdraught of a cumulonimbus at the formation stage.

up draught of a cumulonimbus at the growth stage.

downdraught of a cumulonimbus at the mature stage.

#21. During the life cycle of a thunderstorm, which stage is characterized predominantly by downdrafts?

Anvil stage

Dissipating stage

Cumulus stage

Mature stage

#22. Continuous up draughts occur in a thunderstorm during the

period in which precipitation is falling.

cumulus stage.

mature stage.

dissipating stage

#23. Where is a squall line to be expected?

In front of a cold front occlusion at higher levels.

At the surface position of a warm front.

In front of an active cold front.

Behind a cold front.

#24. What feature is normally associated with the cumulus stage of a thunderstorm?

Continuous updraft

Roll cloud

Frequent lightning

Rain or hail at the surface

#25. A gust front is

normally encountered directly below a thunderstorm

characterized by heavy lightning

another name for a cold front

formed by the cold air outflow from a thunderstorm

#26. The diameter and the life time of a typical microburst are in the order of

8 km and 5-15 minutes

12 km and 5-10 minutes

4 km and 1-5 minutes

4 km and 30-40 minutes

#27. During which stage of thunderstorm development are rotor winds characterized by roll clouds most likely to occur?

Cumulus stage and mature stage.

Mature stage.

Cumulus stage.

Dissipating stage.

#28. Large hail stones

only occur in frontal thunderstorms

are typically associated with severe thunderstorms

only occur in thunderstorms of mid-latitudes

are entirely composed of clear ice

#29. In which of the following areas is the highest frequency of thunderstorms encountered?

Temperate

Tropical

Polar

Subtropical

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