Atmospheric PressureAviation Meteorology — DGCA CPL practice questions
Question 1 of 50
Around a low-pressure area, the surface winds:
All 50 questions — Atmospheric Pressure
Aviation Meteorology · DGCA CPL. The correct option is marked on each.
Q1. Around a low-pressure area, the surface winds:
- A.Converge✓
- B.Diverge
- C.Blow straight
Why: Surface winds spiral inward into a low.
Q2. Low pressure is generally associated with:
- A.Good weather
- B.Bad weather✓
- C.No particular weather
Why: Lows bring rising air, cloud and bad weather.
Q3. In a high-pressure area the winds are generally:
- A.Normal
- B.Strong
- C.Weak✓
Why: Highs have a slack pressure gradient → light/weak winds.
Q4. Flying from an area of low pressure to high pressure (subscale unchanged), the altimeter will read:
- A.Over-read
- B.Under-read✓
- C.Constant
Why: Low to high → altimeter under-reads.
Q5. Isallobars are lines joining places of equal:
- A.Pressure
- B.Temperature tendency
- C.Pressure tendency✓
Why: Isallobars = equal pressure change over a period.
Q6. An altimeter is which kind of barometer?
- A.Aneroid✓
- B.Mercury
- C.Alcohol
Why: An altimeter is an aneroid barometer calibrated in feet.
Q7. The region between two lows and two highs is called a:
- A.Depression
- B.Secondary low
- C.Col✓
Why: A col is the neutral region between two lows and two highs.
Q8. The relationship between height and pressure is used in the construction of the:
- A.Altimeter✓
- B.Airspeed indicator
- C.Vertical speed indicator
Why: The pressure altimeter converts pressure to height.
Q9. An altimeter measures the height of the aircraft above the:
- A.Mean sea level
- B.1013.2 hPa datum
- C.Datum level set on its subscale✓
Why: It reads height above the pressure datum set on the subscale.
Q10. Two aircraft at the same indicated altitude (1013.2 hPa set), one over a cold air mass and one over a warm air mass. Which has the greater true altitude?
- A.The one over the warm air mass✓
- B.The one over the cold air mass
Why: Warm air is less dense; pressure falls more slowly, so true altitude is greater over warm air.
Q11. The rate of fall of pressure with height in a warm air mass, compared with a cold air mass, is:
- A.The same
- B.More rapid
- C.Less rapid✓
Why: Warm air is less dense → pressure falls less rapidly with height.
Q12. Near MSL, an increase of 1000 ft corresponds to a pressure decrease of about:
- A.100 hPa
- B.1000 hPa
- C.3 hPa
- D.33 hPa✓
Why: Near MSL ≈1 hPa per 30 ft → 1000 ft ≈ 33 hPa.
Q13. Lines drawn through places of equal pressure are called:
- A.Isobars✓
- B.Isotherms
- C.Isogonals
- D.Isoclinals
Why: Isobars join places of equal pressure.
Q14. Semi-diurnal (twice-daily) pressure variations are most pronounced in the:
- A.Polar regions
- B.Middle latitudes
- C.Tropics✓
Why: The atmospheric semi-diurnal pressure tide is strongest in the tropics.
Q15. In the Southern Hemisphere, the wind around a low-pressure area blows:
- A.Clockwise✓
- B.Anticlockwise
- C.Straight across the isobars to the centre
Why: SH lows circulate clockwise.
Q16. When an altimeter on the ground reads the aerodrome elevation, its subscale is set to:
- A.QNH✓
- B.QNE
- C.QFF
- D.QFE
Why: With QNH set, the altimeter reads altitude above MSL = aerodrome elevation on the ground.
Q17. Poor visibility is most often associated with a:
- A.High✓
- B.Low
- C.Col
Why: Highs are stable → haze/fog and poor visibility.
Q18. On either side, perpendicular to a ____, the pressure rises:
- A.Trough✓
- B.Ridge
- C.Low
Why: A trough is a line of lowest pressure; pressure rises away from it on both sides.
Q19. The fall of pressure with height is more rapid in:
- A.Cold areas✓
- B.Warm areas
- C.Humid areas
Why: Cold air is denser → pressure falls more rapidly with height.
Q20. In the ISA, the 300 hPa level corresponds to approximately:
- A.20 000 ft
- B.30 000 ft✓
- C.35 000 ft
Why: 300 hPa ≈ 30 000 ft.
Q21. In the ISA, 18 000 ft corresponds to a pressure of approximately:
- A.700 hPa
- B.200 hPa
- C.500 hPa✓
Why: 18 000 ft ≈ 500 hPa.
Q22. In the ISA, the 200 hPa level corresponds to approximately:
- A.20 000 ft
- B.30 000 ft
- C.40 000 ft✓
Why: 200 hPa ≈ 38 700–40 000 ft.
Q23. In the ISA, 24 000 ft corresponds to a pressure of approximately:
- A.400 hPa✓
- B.500 hPa
- C.300 hPa
Why: 24 000 ft ≈ 400 hPa.
Q24. In the ISA, the 700 hPa level corresponds to approximately:
- A.20 000 ft
- B.10 000 ft✓
- C.18 000 ft
Why: 700 hPa ≈ 10 000 ft.
Q25. In the ISA, 40 000 ft corresponds to a pressure of approximately:
- A.400 hPa
- B.500 hPa
- C.200 hPa✓
Why: 40 000 ft ≈ 200 hPa.
Q26. In the ISA, the 850 hPa level corresponds to approximately:
- A.7 000 ft
- B.5 000 ft✓
- C.10 000 ft
Why: 850 hPa ≈ 5 000 ft.
Q27. An aircraft is gaining true altitude although the altimeter reads a constant altitude. This is because it is:
- A.Standard pressure has risen
- B.Flying towards a high✓
- C.Flying towards a low
- D.Temperature has decreased
Why: Flying toward higher pressure, the altimeter under-reads; holding the indication means climbing.
Q28. A contour of 9160 m would be expected on a constant-pressure chart for the level:
- A.500 hPa
- B.400 hPa
- C.300 hPa✓
- D.200 hPa
Why: 9160 m ≈ 30 000 ft ≈ 300 hPa.
Q29. A steep pressure gradient means:
- A.Contours far apart, weak wind
- B.Contours far apart, strong wind
- C.Isobars far apart, low temperature
- D.Isobars closely packed, strong wind✓
Why: Closely-packed isobars = steep gradient = strong wind.
Q30. The inversion that occurs when a stable layer sinks within a high-pressure area is a:
- A.Negative inversion
- B.Radiation inversion
- C.Subsidence inversion✓
- D.Air-mass inversion
Why: Subsiding air in a high warms adiabatically → subsidence inversion.
Q31. Which condition would cause the true altitude to be greater than the indicated altitude (altimeter constant)?
- A.Warm / Low
- B.Cold / Low
- C.Hot / High✓
- D.Cool / Low
Why: Flying toward hot air and/or high pressure → altimeter under-reads → true altitude greater.
Q32. The vertical air motion associated with a cyclone (low) is:
- A.Descending and subsiding
- B.Ascending and converging✓
- C.Descending and cooling
- D.Ascending and diverging
Why: A low = converging, ascending air.
Q33. An aerodrome is at mean sea level; its QNH is 1014.0 hPa. Its QFF is:
- A.1014.0 hPa✓
- B.1013.25 hPa
- C.Cannot be determined
- D.More than QNH
Why: At MSL, QFE = QNH = QFF.
Q34. The instrument that continuously records atmospheric pressure is the:
- A.Anemograph
- B.Barograph✓
- C.Hygrograph
- D.Barometer
Why: A barograph records pressure. The original option set was missing 'Barograph'; corrected.
Q35. Flying Delhi→Calcutta at a constant indicated altitude and drifting to starboard, the true altitude compared with the indicated altitude will be:
- A.Lower✓
- B.Same
- C.Higher
Why: Drift to starboard means heading toward lower pressure → altimeter over-reads → true altitude lower.
Q36. Which statement about a col is correct?
- A.It brings bad weather with good visibility✓
- B.It always brings fog
- C.It brings strong winds
Why: Reworded from a garbled item: a low/col region often pairs unsettled weather with relatively good visibility.
Q37. Atmospheric pressure at a point is fundamentally due to:
- A.Wind
- B.Temperature
- C.Gravity (weight of the air above)✓
- D.Density
Why: Atmospheric pressure is the weight of the overlying air acting under gravity.
Q38. On a 300 hPa constant-pressure chart, the contours (isohypses) are drawn at intervals of:
- A.20 gpm
- B.40 gpm
- C.60 gpm
- D.80 gpm✓
Why: On the 300 hPa chart the contour interval is 80 gpm.
Q39. On a 500 hPa constant-pressure chart, the contours (isohypses) are drawn at intervals of:
- A.20 gpm
- B.40 gpm✓
- C.60 gpm
- D.80 gpm
Why: On the 500 hPa chart the contour interval is 40 gpm.
Q40. An aerodrome is 160 m AMSL with QNH 1005 hPa (assume 1 hPa = 8 m). Its QFE is:
- A.1015 hPa
- B.985 hPa✓
- C.1005 hPa
- D.975 hPa
Why: 160 m ÷ 8 m/hPa = 20 hPa; QFE = QNH − 20 = 985 hPa.
Q41. The barometric pressure at the airfield datum point is known as the:
- A.QFF
- B.QNH
- C.QFE✓
- D.Standard pressure
Why: QFE = pressure at the aerodrome reference point.
Q42. The pressure of the atmosphere with increasing height:
- A.Decreases at an increasing rate
- B.Decreases at a constant rate
- C.Decreases at a decreasing rate✓
- D.Is constant above the tropopause
Why: Pressure falls at a decreasing rate with height.
Q43. Atmospheric pressure may be defined as:
- A.The weight of the atmosphere on any surface
- B.The weight of the atmosphere at sea level
- C.The force per unit area exerted by the atmosphere on any surface with which it is in contact✓
- D.A pressure of 1013.2 hPa
Why: Pressure = force per unit area exerted by the atmosphere.
Q44. The QFF is the atmospheric pressure:
- A.At the place where the reading is taken
- B.Corrected to MSL assuming ISA conditions
- C.At the place of reading corrected to MSL using the prevailing (actual) temperature✓
- D.As measured at the aerodrome reference point
Why: QFF = QFE reduced to MSL using the actual temperature.
Q45. A pressure of 1013 hPa is known as the:
- A.Standard pressure setting✓
- B.QNH
- C.QFE
- D.QFF
Why: 1013.25 hPa = Standard Pressure Setting.
Q46. The altimeter reads zero at aerodrome level when the subscale is set to:
- A.QFF
- B.QNH
- C.SPS
- D.QFE✓
Why: With QFE set, the altimeter reads zero at aerodrome level.
Q47. The aerodrome QNH is the aerodrome pressure:
- A.Corrected to MSL assuming ISA conditions✓
- B.Corrected to MSL assuming isothermal conditions
- C.Corrected for temperature and reduced to MSL using the actual atmosphere
- D.Uncorrected
Why: QNH = QFE reduced to MSL using the ISA.
Q48. An isobar on a meteorological (analysis) chart joins all places having the same:
- A.QFE
- B.QFF✓
- C.QNH
- D.Standard pressure
Why: Isobars on analysis charts are drawn for corrected MSL pressure.
Q49. Pressure will ____ with increasing height, being about ____ at 10 000 ft and ____ at 30 000 ft:
- A.Increase / 800 / 400 hPa
- B.Decrease / 700 / 300 hPa✓
- C.Increase / 200 / 800 hPa
- D.Decrease / 500 / 200 hPa
Why: ≈700 hPa at 10 000 ft and ≈300 hPa at 30 000 ft.
Q50. An airfield is 100 m AMSL, QFF 1030 hPa, surface temperature −15°C. The QNH is:
- A.Impossible to determine
- B.Less than 1030 hPa✓
- C.Same as QFF
- D.More than 1030 hPa
Why: Above MSL and colder than ISA → QFF exceeds QNH, so QNH < 1030 hPa.