DGCA Meteorology: Mountain Waves Questions
44 exam-style Mountain Waves questions for the DGCA Meteorology paper (CPL · ATPL · PPL). The first 12 are free below with answers and explanations — sign up free to practise all of them with progress tracking.
-
Q1
At the top of orographic waves, in mountainous regions, the cloud most likely to be encountered is
- A cirrus.
- B cumulus mediocris
- C altocumulus lenticularis.
Show answer
Correct answer: C. altocumulus lenticularis.
Standing waves set up downwind of mountains produce smooth, lens-shaped altocumulus lenticularis at the wave crests, the classic visual signature of mountain-wave activity.
-
Q2
For mountain waves to form the wind speed for small mountains should be atleast
- A 15 m/s
- B 10 m/s
- C 7 m/s
Show answer
Correct answer: C. 7 m/s
For mountain waves over small hills or ridges, the wind component across the ridge should be at least about 7 m/s (roughly 15 kt); larger mountain ranges require about 15 m/s.
-
Q3
Rotor clouds are associated with:
- A Turbulence above the cloud
- B Turbulence below the cloud
- C No turbulence
Show answer
Correct answer: B. Turbulence below the cloud
Rotor clouds form under mountain waves, with choppy air below from swirling winds.
-
Q4
For mountain waves to form the wind speed for large mountains should be atleast
- A 7 m/s
- B 15 m/s
- C 10 m/s
Show answer
Correct answer: B. 15 m/s
For mountain waves to form over large mountain ranges, the wind component across the ridge should be at least about 15 m/s (roughly 30 kt), roughly double the requirement for small hills.
-
Q5
At the top of orographic waves, in mountainous regions, the cloud most likely to be encountered is
- A altocumulus lenticularis.
- B cirrostratus.
- C cumulus mediocris.
Show answer
Correct answer: A. altocumulus lenticularis.
The crests of orographic (lee) waves are marked by altocumulus lenticularis, smooth lens-shaped clouds that remain quasi-stationary as air condenses on the rising side of the wave and evaporates on the descending side.
-
Q6
For mountain waves to form the wind speed for large mountains should be atleast
- A 10 m/s
- B 7 m/s
- C 15 m/s
Show answer
Correct answer: C. 15 m/s
Over large mountain ranges a cross-ridge wind of at least about 15 m/s (around 30 kt) is required for mountain-wave formation, compared with about 7 m/s for small hills.
-
Q7
The vertical extent of the friction layer depends primarily on
- A roughness of surface, temperature, local time
- B temperature, local time, environmental lapse rate
- C stability, wind speed, roughness of surface
- D wind speed, roughness of surface, temperature
Show answer
Correct answer: C. stability, wind speed, roughness of surface
This Explanation is Coming Soon
-
Q8
Low level wind shear is likely to be greatest
- A at the top of a marked surface-based inversion
- B at the condensation level when there is no night radiation.
- C at the condensation level when there is strong surface friction
- D at the top of the friction layer
Show answer
Correct answer: A. at the top of a marked surface-based inversion
This Explanation is Coming Soon
-
Q9
Which cloud type may indicate the presence of severe turbulence?
- A Cirrocumulus
- B Nimbostratus
- C Altocumulus lenticularis
- D Stratocumulus
Show answer
Correct answer: C. Altocumulus lenticularis
This Explanation is Coming Soon
-
Q10
Low level vertical wind shear can be expected during the night
- A in association with radiation inversions
- B in unstable atmospheres
- C and early morning only in winter
- D and early morning only in summer
Show answer
Correct answer: A. in association with radiation inversions
This Explanation is Coming Soon
-
Q11
What is the effect of a strong low level inversion?
- A It results in good visual conditions
- B It promotes vertical windshear.
- C It promotes extensive vertical movement of air.
- D It prevents vertical windshear
Show answer
Correct answer: B. It promotes vertical windshear.
This Explanation is Coming Soon
-
Q12
A wide body aircraft takes off on a clear night in Dhahran, Saudi Arabia. Shortly after take off the aircraft’s rate of climb drops to zero. This can be due to
- A very pronounced downdrafts
- B low relative humidity
- C a very strong temperature inversion
- D sand/dust in the engines
Show answer
Correct answer: C. a very strong temperature inversion
This Explanation is Coming Soon
The full bank
32 more Mountain Waves questions in the full bank
Create a free account to practise every Mountain Waves question with instant scoring, chapter tests, previous DGCA papers and full-length mock exams.
More DGCA Meteorology topics