Vertical Motion and CloudsAviation Meteorology — DGCA CPL practice questions
Question 1 of 39
Drizzle falls from:
All 39 questions — Vertical Motion and Clouds
Aviation Meteorology · DGCA CPL. The correct option is marked on each.
Q1. Drizzle falls from:
- A.Cirrostratus (CS)
- B.Stratus (ST)✓
- C.Nimbostratus (NS)
- D.Cumulus (CU)
Why: Drizzle falls from stratus.
Q2. Altostratus (AS) is:
- A.A low sheet cloud
- B.A medium-level sheet cloud✓
- C.A cloud of large vertical growth
- D.A high sheet cloud
Why: AS is a medium sheet cloud.
Q3. Showers fall from:
- A.Cumulus (CU)
- B.Cumulonimbus (CB)✓
- C.Altostratus (AS)
- D.Altocumulus (AC)
Why: Showery precipitation comes from convective CB/CU; CB gives the classic shower.
Q4. Heavy (severe) airframe icing is most likely in:
- A.Cirrus (CI)
- B.Cirrostratus (CS)
- C.Stratus (ST)
- D.Cumulonimbus (CB)✓
Why: CB holds large supercooled droplets → severe icing.
Q5. To avoid icing, a pilot should prefer a cloud showing which optical phenomenon?
- A.Halo✓
- B.Corona
- C.Iridescence (multicoloured cloud)
Why: A halo means ice crystals → low icing; corona/iridescence means supercooled water.
Q6. The dark-grey cloud giving continuous rain is:
- A.Altostratus (AS)
- B.Nimbostratus (NS)✓
- C.Stratus (ST)
- D.Cumulonimbus (CB)
Why: Nimbostratus gives continuous rain.
Q7. A uniform layer of cloud resembling fog but not touching the ground is:
- A.Altostratus (AS)
- B.Nimbostratus (NS)
- C.Stratus (ST)✓
Why: Stratus is fog-like layer cloud lifted off the surface.
Q8. The feathery cloud composed of ice crystals is:
- A.Cirrus (CI)✓
- B.Cirrostratus (CS)
- C.Altostratus (AS)
Why: Cirrus — high, feathery, ice-crystal cloud.
Q9. Nimbostratus (NS) cloud occurs at a:
- A.Cold front
- B.Warm front✓
Why: NS is associated with the gentle uplift of a warm front.
Q10. A halo is associated with which cloud?
- A.Altocumulus (AC)
- B.Altostratus (AS)
- C.Cirrostratus (CS)✓
- D.Cirrus (CI)
Why: Halo forms in cirrostratus.
Q11. A corona is associated with which cloud?
- A.Altostratus (AS)
- B.Altocumulus (AC)✓
- C.Cirrocumulus (CC)
- D.Cirrostratus (CS)
Why: Corona forms in thin water-droplet cloud such as altocumulus.
Q12. Lenticular clouds indicate the presence of:
- A.A warm front
- B.A cold front
- C.Mountain waves✓
Why: Lenticular clouds mark standing mountain waves.
Q13. The lowest level below which condensation (contrails) will NOT form is the:
- A.Mintra level✓
- B.Drytra level
- C.Maxtra level
Why: Mintra = minimum trail level.
Q14. Rain falling from a cloud but not reaching the ground is:
- A.Virgo
- B.Virga✓
- C.Mirage
Why: Virga = precipitation evaporating before reaching the surface.
Q15. A cumulonimbus with a distinct anvil is:
- A.Castellanus
- B.Capillatus✓
- C.Uncinus
Why: CB capillatus has the fibrous anvil top.
Q16. The cloud ceiling is the height of the lowest cloud covering:
- A.3–4 oktas
- B.8 oktas
- C.5 oktas or more✓
Why: Ceiling = lowest broken/overcast layer.
Q17. Condensation trails do NOT form above the:
- A.Maxtra level✓
- B.Drytra level
- C.Mintra level
Why: Maxtra = maximum trail level.
Q18. A cloud is of operational significance when its base is below ____ m, or below the highest minimum sector altitude, whichever is greater:
- A.1500✓
- B.2000
- C.1000
Why: 1500 m is the operational-significance threshold.
Q19. Altocumulus with cumuliform protuberances (castellanus/floccus) indicates:
- A.Stability
- B.Instability✓
- C.Neutrality
Why: AC castellanus signals mid-level instability.
Q20. Hail may be experienced under the anvil of a CB:
- A.True✓
- B.False
Why: Hail can be thrown out and fall from beneath the anvil.
Q21. If DALR = 9.8°C/km and ELR = 6.8°C/km, the (dry) atmosphere is:
- A.Stable✓
- B.Unstable
- C.Indifferent
Why: ELR < DALR → stable for unsaturated air.
Q22. If SALR = 5.5°C/km and ELR = 4.5°C/km, the (saturated) atmosphere is:
- A.Unstable
- B.Stable✓
- C.Indifferent
Why: ELR < SALR → absolutely stable.
Q23. When DALR > ELR > SALR, the atmosphere is:
- A.Conditionally unstable✓
- B.Latently stable
- C.Potentially stable
Why: SALR < ELR < DALR is 'conditional instability'. Corrected the term from 'conditionally stable'.
Q24. Unsaturated (dry) air is unstable when:
- A.ELR = DALR
- B.ELR > DALR✓
- C.ELR < DALR
Why: ELR steeper than the DALR → dry instability.
Q25. Saturated air is unstable when:
- A.SALR = ELR
- B.ELR > SALR✓
- C.ELR < SALR
Why: ELR steeper than SALR → saturated instability.
Q26. If ELR = SALR = DALR, the atmosphere is:
- A.Stable
- B.Unstable
- C.Indifferent (neutral)✓
Why: All rates equal → neutral/indifferent.
Q27. Surface temperature is 30°C. Using the DALR, the temperature at 2 km is:
- A.18°C
- B.10°C✓
- C.42°C
Why: 30 − 2×10 = 10°C.
Q28. An isothermal atmosphere is:
- A.Stable✓
- B.Unstable
- C.Neutral
Why: Isothermal layers are very stable.
Q29. If the ELR is less than the SALR, the atmosphere is:
- A.Absolutely unstable
- B.Conditionally stable
- C.Absolutely stable✓
Why: ELR < SALR → absolutely stable.
Q30. The DALR is approximately:
- A.5°C/km
- B.15°C/km
- C.10°C/km✓
Why: ≈9.8 ≈ 10°C/km.
Q31. The SALR near mean sea level is about:
- A.10°C/km
- B.5°C/km✓
- C.5°F/km
Why: ≈4–5°C/km at MSL.
Q32. The SALR approaches the DALR:
- A.At 0°C
- B.At 15°F
- C.At about −40°C✓
Why: At very cold temperatures little latent heat is released, so SALR → DALR.
Q33. Dry air at 35°C forced to rise 1 km adiabatically attains:
- A.29°C
- B.25°C✓
- C.45°C
Why: 35 − 10 = 25°C.
Q34. An inversion in the atmosphere indicates:
- A.Stability✓
- B.Instability
- C.Neutrality
Why: An inversion is extremely stable.
Q35. An inversion is a ____ lapse rate:
- A.Positive
- B.Negative✓
- C.Neutral
Why: Temperature rising with height = negative lapse rate.
Q36. The ELR can be greater than the DALR:
- A.True✓
- B.False
Why: A superadiabatic ELR occurs over strongly heated surfaces.
Q37. The process that largely determines the vertical temperature distribution of the atmosphere is:
- A.Adiabatic✓
- B.Isothermal
- C.Isentropic
Why: Adiabatic ascent/descent of air governs the vertical temperature profile.
Q38. A rise of temperature with height is called:
- A.An inversion✓
- B.A lapse
- C.Normal
Why: Inversion = temperature increasing with height.
Q39. Inversions are most common in:
- A.Post-monsoon
- B.Monsoon
- C.Winter✓
Why: Long clear winter nights favour radiation inversions.