Basic Aerodynamics – Class Instructions Onboarding – Parham A. Personal Testing Center

"*" indicates required fields

1- The atmosphere exists from:*

A) The ground level up to where air molecules exists

B) From sea level up to 50 km

C) None.

2- The atmosphere exists in ______ near the earth.*

A) Free molecular conditions

B) Continuum conditions

C) Transitional

3- What is the purpose of studying the atmosphere?*

A) To predict the lifespan of jet engines regardless of maintenance.

B) To calculate the exact weight of an aircraft.

C) Understanding the environment in which aircraft operate in and the impact on its performance.

4- Aerodynamics is "the investigation of forces acting on a flying object"*

A) TRUE

B) FALSE

C) N/A

5- Which of the following is correct composition of atmosphere"*

A) 78% Oxygen, 21% Nitrogen, 0.5% Water Vapor, 0.5% Other Gases

B) 80% Nitrogen, 15% Oxygen, 2% Argon, 3% Other Gases

C) 78% Nitrogen, 21 Oxygen, 1% Other Gases

6- The total mass of atmosphere is: (EASA reference only)*

A) 54 × 10^16kg

B) 5.15 × 10^18

C) 54 × 10^18

7- In the altitude of _____ the atmosphere reachs half of its mass.*

A) 18,000 ft.

B) 1000 km

C) 25,000 ft.

8- Which of the following options indicate the formula for the "Pressure"?*

A) ρ = F / A

B) P = F / A

C) P = A / F

9- With increase in altitude the pressure _________ .*

A) Decreases

B) Increases

C) Remains the same

10- Which of the following is the temperature conversion factor for "Celsius to Kelvin"*

A) C° + 273 = K°

B) 9 / 5 C°+ 32 = K°

C) (F − 32) × 5 ⁄ 9 + 273.15 = K°

11- Which of the following is the temperature conversion factor for "Celsius to Farenhit"*

A) C° + 273 = F°

B) 9 / 5 C°+ 32 = F°

C) (C°− 32) × 5 ⁄ 9 + 273.15 = K°

12- "ρ = m / V" is the formula for*

A) Density

B) Viscosity

C) Mass

13- The ISA temperature lapse rate is _____ .*

A) 4 C° per 1000 ft.

B) 1 F° per 1000 ft.

C) 2 C° per 1000 ft.

14- The elevation of Tehran Mehrabad Int'l is approximately 4000 ft. MSL. If the standard sea level temperature is 15 C°, what is the temperature at the mentioned aerodrome?*

A) 7 °C

B) 14 °C

C) 15 °C

15- Considering the ISA conditions, what is the temperature in the tropopause?*

A) 70 °C

B) -47 °C

C) -57 °C

16- In [Figure-1] what is the layer (C) and in what extend of altitude does it exist?*

A) Stratosphere, 19-22 miles

B) Mesosphere, 45-51 miles

C) Troposphere, 50,000 ft.-60,000ft.

17- In [Figure-1] what is the layer (A) and in what extend of altitude does it exist?*

A) Stratosphere, 19-22 miles

B) Mesosphere, 45-51 miles

C) Troposphere, 50,000 ft.-60,000ft. in the equator and 20,000ft - 30,000ft in the pole

18- 1 atm of pressure is equivalent to:*

A) 1013.5 hPa

B) 13.7 p.s.i.

C) 1013.2 hPa

19- The formula "1/2ρ V^2 S CL" represents*

A) Viscosity

B) Lift

C) Drag

20- If airspeed doubles, by what factor does lift change (assuming other variables constant)?*

A) 2

B) 8

C) 4

21- A wing has surface of 20m^2, at sea level. Velocity of 50m/s and lift coefficient of 0.6. Compute the lift.*

A) 9,188 N

B) 18,375N

C) 36,750 N

22- A wing has surface of 20m^2, at sea level. Velocity of 50m/s and lift coefficient of 0.6. Compute the lift.*

A) 9,188 N

B) 18,375N

C) 36,750 N

23- At 0° angle of attack, which airfoil produces lift?*

A) Asymmetrical

B) Symmetrical

C) Neither

24- After stall, what happens to lift?*

A) It remains constant

B) It suddenlydecreases

C) It increases

25- For a symmetrical airfoil if the lift is 0, the AOA is ______ .*

A) Zero

B) Positive

C) Negative

26- In equator, the height of Troposphere is _________ .*

A) 20,000 - 30,000 ft.

B) 50,000 - 60,000 ft.

C) 1,000 km

27- In a very hot and humid day, an aircraft needs ________ length of runway for takeoff.*

A) More

B) Standard

C) Less

28- In [Figure-2] what is (2)?*

A) Trailing Edge (TE)

B) Leading Edge

C) Thickness

29- In [Figure-2] what is (6)?*

A) Trailing Edge (TE)

B) Leading Edge

C) Thickness

30- Which one of the following options defines "Mean Camber Line"?*

A) The imaginary curve the splits the airfoil into two parts and connects LE to the TE

B) The boundary layer on the top of an airfoil

C) The line that directly connects LE to TE

31- In which type of airfoils does the chord line and the mean camber line overlap on each other?*

A) Semi-assymetrical

B) Symmetrical

C) Assymetrical

32- Combination of molecular oxygen with atomic oxygen results in fomation of:*

A) Ozone layer

B) Tropopause

C) Change in density

33- Aerodynamic efficiency of a wing is analyzed using which of the following formulas?*

A) L / D

B) ρ × V^2 - CL

C) 1/2 ρ V^2 S +

34- Aerodynamic efficiency of a wing is analyzed using which of the following formulas?*

A) L / D

B) ρ × V^2 - CL

C) 1/2 ρ V^2 S +

35- Which of the following options defines "Absolute Humidity"?*

A) Ratio of the amount of water exsiting in the capacity of atmosphere in a certain condition.

B) Actual amount of water present in the atmosphere.

C) Ratio of density to the temperature

36- The relative humidity is expressed in term of:*

A) Percentage

B) Weight (mass)

C) Volume

37- ______ is the temperature in which the humidity of the air turns into liquid form (e.g. pricipitation)*

A) Dewpoint

B) Stagnation point

C) Neither

38- Aspect ratio of a wing can mathematically represented by:*

A) Wing span[squared] / wing surface

B) Wing surface / Wing span[squared]

C) 2×wing span / Wing surface

39- The aspect ratio for a rectangular wing is:*

A) AR = S / B^2

B) AR = B^2 / S

C) AR = B / S

40- A wing has a span of 20 m and an area of 40 m^2, Compute the aspect ratio.*

A) 1/2

B) 2

C) 2/3

41- A rectangular wing with aspect ratio of 8 has wing span of 16 m. What is its wing surface?*

A) 2

B) 4

C) 1

42- Angle of incidence is the angle between*

A) Chord line and longitudinal axis

B) Mean camber line and lower surface of the wing

C) Relative wind and chord line

43- ________ is equals the speed and opposes the motion of an aircraft.*

A) Relative wind

B) AOA

C) Neither

44- What is the purpose of imposing angle of incidence on aircraft?*

A) Reduction of wing loading

B) So the wing has AOA during cruise for better performance.

C) Enhanncing wing design ergonomy

45- Which one of the Newton's laws of motion states: "Every action has a equal and opposite reaction"*

A) 2nd law

B) 1st law

C) 3rd law

46- Which one of the Newton's laws of motion states: "Every action has a equal and opposite reaction"*

A) 2nd law

B) 1st law

C) 3rd law

47- Which of the following options represents formula for Mass Flow Rate (ṁ)?*

A) ρVA

B) ρ = m / A

C) m = ρ × A

48- The purpose of using Continuity Principle is to decrease speed of a fluid flow without consumption of energy.*

A) True

B) False

49- What relation does [Equation-1] represents*

A) Bernouli's principle

B) Continuity

C) Reynolds number

50- Troposphere's altitude is more in _______ than _______ .*

A) Summer, winter

B) Winter, summer

C) No difference.

51- The International Standard Atmosphere (ISA) considers _______ as the reference.*

A) Mean Sea Level

B) Ground Level

C) Specified reporting station.

52- Location of maximum thickness is presented respective to the chord in percent.*

A) False

B) True

C) N/A

53- Location of maximum thickness is presented respective to the chord in percent*

A) True

B) False

54- "Fineness Ratio" is defined as the ratio of the chord of the airfoil to its maximum thickness.*

A) True

B) False

55-

First Choice

Second Choice

Third Choice

This field is for validation purposes and should be left unchanged.