The Atmosphere and Its PropertiesAircraft & Engines — DGCA CPL practice questions
Question 1 of 5
Air density is directly proportional to:
All 5 questions — The Atmosphere and Its Properties
Aircraft & Engines · DGCA CPL. The correct option is marked on each.
Q1. Air density is directly proportional to:
- A.Static pressure✓
- B.Temperature
- C.Humidity
- D.Altitude
Why: Density varies directly with static pressure and inversely with temperature and humidity — which is why density falls as you climb.
Q2. In the ICAO Standard Atmosphere, temperature falls steadily with altitude up to about:
- A.18,000 ft
- B.26,000 ft
- C.36,000 ft✓
- D.46,000 ft
Why: ISA temperature decreases up to roughly 36,000 ft, then remains constant through the lower stratosphere.
Q3. Dynamic pressure is given by the formula:
- A.q = ρ v
- B.q = ½ ρ v²✓
- C.q = 2 ρ v²
- D.q = ρ / v²
Why: Dynamic pressure is the kinetic energy of the air per unit volume: q = ½ ρ v², where ρ is density and v is TAS.
Q4. A pitot tube facing into the airflow senses:
- A.Static pressure only
- B.Dynamic pressure only
- C.Total (static + dynamic) pressure✓
- D.Density
Why: The pitot tube senses Total (Pitot) Pressure = Static + Dynamic; the static vent, parallel to the flow, senses static pressure alone.
Q5. The correct order of airspeed corrections from indicated to true airspeed is:
- A.IAS → EAS → CAS → TAS
- B.IAS → CAS → EAS → TAS✓
- C.IAS → TAS → CAS → EAS
- D.CAS → IAS → EAS → TAS
Why: IAS corrected for position/pressure error gives CAS; CAS corrected for compressibility gives EAS; EAS corrected for density gives TAS.