Question Analysis, Book Reference, Important Concepts, Formulae and topic wise Solutions for the topic "Atmosphere: Properties and Standard Atmosphere"

1. FLIGHT MECHANICS
ATMOSPHERE: PROPERTIES & ISA
TOPIC WISE SOLVED QUESTIONS
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2. 2Question Analysis | Book Reference | Important Concepts | Formulae | Solutions
FLIGHT MECHANICS
GATE 2015 Atmosphere: Properties, standard atmosphere 1 Mark
Q1. Consider the density and altitude at the base of an isothermal layer in the standard atmosphere to be 𝜌1
and ℎ1, respectively. The density variation with altitude (𝜌 versus h) in that layer is governed by (𝑅: specific
gas constant, 𝑇: temperature, 𝑔𝑜: acceleration due to gravity at sea level)
(A) (B)
(C) (D)
Answer:
(A)
Formula:

3. 3
FLIGHT MECHANICS
GATE 2008 Atmosphere: Properties, standard atmosphere 2 Mark
Q2. Which of the following statements is TRUE as the altitude increase in stratosphere of International
Standard Atmosphere?
(A) Temperature increases and dynamic viscosity decreases
(B) Temperature remains constant and pressure increase
(C) Temperature decrease and sound speed decreases.
(D) Temperature remains constant and density decreases
Explanation:
In general temperature is considered to be constant or increase in the
stratosphere (11-50km), the dynamic viscosity (Gases) and speed of
sound, increase with temperature. We also know that pressure and
density decreases with increase in altitude.
Answer:
(D) Temperature remains constant and density decreases
Note: Dynamic viscosity decreases with temperature for liquids
ByCmglee-Ownwork,CCBY-SA3.0
Question Analysis | Book Reference | Important Concepts | Formulae | Solutions

4. 4
FLIGHT MECHANICS
GATE 2018 Atmosphere: Properties, standard atmosphere 2 Mark
Q3. Assuming ISA standard sea level conditions (288.16 K, density of 1.225 kg/m3, g = 9.81 m/s2, R = 287
J/(kg-K)), the density (in kg/m3) of air at Leh, which is at an altitude of 3500 m above mean sea level is
________ (accurate to two decimal places)
Answer: 0.85 to 0.88
Solution:
Question Analysis | Book Reference | Important Concepts | Formulae | Solutions

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