What is the most common process by which cloud is formed?

• Adiabatic cooling of rising air

• Cooling of air by conduction at the earth’s surface

• Cooling of air when it is transported over cold surfaces

• Mixing of moist air with colder drier air

In mid-latitudes, what is the range of cloud base height above the Earth’s surface which will classify clouds as ‘middle cloud’?

• Below 6,500 ft

• Between 6,500 ft to 23,000ft ft

• Between 4,500 ft to 23,000 ft

• Between 10, 000 to 25, 000 ft

What type of cloud is the most likely to form if moist air is cooled adiabatically in an area with an ELR of 1°/1000’?

• Cumuliform

• Cumulonimbus

• Stratiform

• Orographic

What flight conditions will be most likely encountered when a pilot flies towards a layer of convective clouds?

• Smooth flying and reduced visibility beneath the base

• Smooth flying in the cloud

• Good visibility above the cloud and turbulent conditions below

• Turbulence above the cloud with poor visibility below the base

Which of the following words describes rain-bearing clouds?

• Cirrus

• Cumulus

• Nimbus

• Stratus

What are the two main classifications of clouds?

• Cirroform and Cumuliform

• Stratiform and Cumuliform

• Nimbus and Layered

• Alto and Cumuliform

Which form of lifting is most likely to result in the formation of Nimbostratus (Ns) cloud?

• Orographic lifting on the windward side of mountain ranges

• Mechanical turbulence from surface friction

• Frontal lifting and/or widespread ascent of air

• Convection from surface heating

What is the most likely process by which cloud forms on windy mornings?

• Convergence

• Orographic ascent

• Slow widespread ascent

• Turbulence or small-scale mechanical rising

Select the appropriate set of words from the A to D list below that when added to the end of this text and make a true statement:

"A contrail is a cloud made of ice crystals that is formed by moisture supplied to the atmosphere by …"

• Turbulence mixing in the upper atmosphere

• Jet aircraft engine exhaust gases

• Jet stream wind

• Products produced in Cb anvil heads

What are Cirriform cloud mainly composed of?

• Ice crystals

• Mixture of water droplets and Ice Crystals

• Super-cooled water droplets

• Water droplets