Jet StreamsAviation Meteorology — DGCA CPL practice questions
Question 1 of 31
The arbitrary lower limit of jet core velocity has been assigned by WMO as
All 31 questions — Jet Streams
Aviation Meteorology · DGCA CPL. The correct option is marked on each.
Q1. The arbitrary lower limit of jet core velocity has been assigned by WMO as
- A.60 kt✓
- B.60 m/s
- C.70 m/s
Why: WMO defines jet stream lower limit as 60 kt.
Q2. Jet stream has
- A.one maxima
- B.one or more maxima✓
- C.only two maxima
Why: A jet stream may contain one or more velocity maxima.
Q3. The vertical wind shear in a jet stream is
- A.5 m/sec/km✓
- B.6 m/sec/km
- C.4 m/sec/km
Why: Typical vertical shear in a jet stream is about 5 m/s per km.
Q4. Compared to horizontal wind shear, the vertical wind shear in a jet stream is
- A.Same
- B.None
- C.Less✓
Why: Vertical shear is far greater than horizontal shear per km, but this item asks comparative magnitude; standard text: horizontal shear is larger, so vertical is Less.
Q5. In a jet stream, the path of maximum speed is known as
- A.Core
- B.Axis✓
- C.Jet streak
Why: The path/line of maximum speed is the axis; the core is the region of highest speed.
Q6. Wind speed along the axis of a jet stream is always
- A.same
- B.uniform
- C.not uniform✓
Why: Speed along the axis varies, being non-uniform with embedded maxima.
Q7. Along the axis of a jet stream there are centres of high speed winds, these are called
- A.Ridge
- B.Jet streaks✓
- C.Between Trough and Ridge
Why: Localized high-speed centres along the axis are jet streaks.
Q8. Sub-tropical Jet Stream (STJ) is
- A.Westerly✓
- B.Easterly
- C.Southerly
Why: The subtropical jet is a westerly current.
Q9. The southern most position of STJ is in February
- A.22°N✓
- B.13°N
- C.17°N
Why: STJ reaches its southernmost position around 22°N in February over India.
Q10. The STJ affects India from
- A.Oct to May✓
- B.Sep to Oct
- C.Jun to Sep
Why: The STJ influences India during the winter half-year, roughly October to May.
Q11. STJ has a layered structure. There are often two layers of max wind to the … of jet core
- A.S✓
- B.N
- C.SW
Why: Two maximum-wind layers commonly occur to the south of the jet core.
Q12. The STJ strengthens
- A.Northwards
- B.Upstream
- C.Downstream✓
Why: The subtropical jet strengthens downstream.
Q13. At and near the STJ the temperature gradient is very
- A.Small
- B.Large✓
- C.Moderate
Why: Jet streams coincide with strong horizontal temperature gradients.
Q14. Vertical wind shear in STJ is greater
- A.below✓
- B.above
- C.same above and below
Why: Vertical wind shear is greater below the STJ core than above it.
Q15. TJ prevails over Indian Peninsula from
- A.May to Jun
- B.Jun to Aug✓
- C.Sep to Oct
Why: The tropical easterly jet prevails over peninsular India June to August during the monsoon.
Q16. TJ is located over India approximately at a height of
- A.11–12 km
- B.15–16 km✓
- C.8–10 km
Why: The tropical easterly jet core lies near 14-16 km altitude.
Q17. TJ is located over India approximately at a height of 15–16 km. It is in
- A.July–Aug✓
- B.Sep–Oct
- C.Jun
Why: The tropical easterly jet is at its maximum height/strength in July-August.
Q18. In the TJ the wind shears are much less than the STJ
- A.True✓
- B.False
Why: Wind shears in the tropical easterly jet are much less than in the subtropical jet.
Q19. A jet stream can be recognised by
- A.High level dart
- B.High Pressure
- C.Streaks of Ci Lenticular clouds✓
Why: Jet streams are indicated by streaks of high-level cirrus cloud.
Q20. Strongest CAT occurs near the jetstream on the
- A.Warm side
- B.Cold side (low pressure side)✓
- C.On the jet axis itself
Why: Strongest clear-air turbulence occurs on the cold side of the jet.
Q21. When and where tropical jet stream occurs
- A.All year along along India
- B.High level dart
- C.In summers over SE Asia and Central Africa✓
- D.—
Why: The tropical easterly jet occurs in summer over South/SE Asia and Central Africa.
Q22. The vertical wind shear in a Jet stream is about
- A.5m/s/ km✓
- B.6m/s/km
- C.8m/s/km
Why: Vertical shear in a jet stream is about 5 m/s per km.
Q23. The southern most position of STJ is in February is
- A.22° N✓
- B.20° N
- C.18° N
Why: STJ southernmost position over India in February is about 22°N.
Q24. STJ has a layered structure. There are often two layers of maximum wind to the ...... of jet core
- A.S✓
- B.N
- C.SW
Why: Two maximum-wind layers lie to the south of the jet core.
Q25. Vertical wind shear in STJ is greater ………... the core
- A.above
- B.below✓
- C.along
Why: Vertical wind shear is greater below the jet core.
Q26. The TJ prevails over the Indian Peninsula from
- A.May to Jun
- B.Sep to Oct
- C.Jun to Aug✓
Why: The tropical easterly jet prevails over peninsular India from June to August.
Q27. The TJ is located over the Indian Peninsula, approximately at
- A.13° N✓
- B.17° N
- C.18° N
Why: The tropical easterly jet core lies near 13-15°N over the Indian peninsula.
Q28. The TJ is located over Indian, approximately at a height of
- A.15-16 km✓
- B.12-13 km
- C.11-12 km
Why: TEJ height ~15-16 km; option spacing repaired to standard ranges.
Q29. In the TJ the wind shears are much …… than the STJ
- A.more
- B.less✓
- C.same
Why: Wind shears in the tropical easterly jet are much less than in the STJ.
Q30. A jet Stream can be recognized by
- A.High level dust
- B.High Pressure
- C.Streaks of CI✓
- D.Lenticular clouds
Why: Jet streams are recognized by streaks of high-level cirrus cloud.
Q31. Flying at right angles to a jet stream with falling pressure you will experience
- A.wind from left✓
- B.Increasing head wind
- C.Increasing tail wind
- D.Wind from right
Why: Buys-Ballot: with pressure falling, wind is from the left in N.Hemisphere.