This set of Spaceflight Mechanics Multiple Choice Questions & Answers (MCQs) focuses on “Planetary Atmosphere”.
1. What is meant by the term ‘Atmosphere’?
a) It is a thin blanket of gases surrounding a planet or an object
b) It is a hard shell of gases around planets
c) It is a liquid present on some planets
d) It is a temporary phenomenon due to solar radiations
View Answer
Explanation: The term ‘Atmosphere’ can be defined as a thin blanket of gases surrounding a planet or an object in outer space. As it is made up of gases, it cannot be a hard shell. It is not caused due to solar radiations.
2. Atmosphere is only related to planets.
a) True
b) False
View Answer
Explanation: Atmosphere is not limited only to planets. Stars also have an outer atmosphere, generally referred to as Stellar Atmosphere. Celestial objects like comets also possess their own atmosphere.
3. The most common gas in the atmosphere of our solar system is ______
a) Nitrogen
b) Hydrogen
c) Helium
d) Carbon dioxide
View Answer
Explanation: Helium is the most common gas in the atmosphere of our solar system. It comprises of a significant portion in the atmosphere of Sun, Mercury, Moon, Jupiter, Saturn, Uranus and Neptune. The second common gas in the solar system is Hydrogen gas, followed by Nitrogen and Carbon dioxide gas.
4. Which gas is the major component of any stellar atmosphere?
a) Nitrogen
b) Helium
c) Oxygen
d) Hydrogen
View Answer
Explanation: Stellar atmosphere refers to the atmosphere of the stars. It is mainly comprised of Hydrogen, which is about 70% of the total atmosphere by mass. The second major component of stellar atmosphere is Helium, which is about 25% of the total atmosphere by mass.
5. In our solar system, the planetary atmosphere with the highest percentage of oxygen is _____
a) Earth
b) Mercury
c) Jupiter
d) Saturn
View Answer
Explanation: The atmosphere of Mercury has 42% of oxygen, which makes it the highest percentage in the solar system. Earth’s atmosphere contains 21% of oxygen whereas Jupiter & Saturn contains negligible amounts of oxygen in their atmosphere.
6. There are two types of planetary atmosphere: Primary atmosphere and Secondary atmosphere.
a) True
b) False
View Answer
Explanation: Every planetary atmosphere can be divided into primary and secondary atmosphere. The primary atmosphere comes from nebular disk whereas the secondary atmosphere comes from the interior of the planet.
7. Which is not an affecting factor for planetary atmosphere?
a) Planet’s Gravity
b) Chemical composition of atmosphere
c) Planetary magnetic field
d) Core of the planet
View Answer
Explanation: Out of the options, Core of the planet is incorrect. The planetary atmosphere varies with difference in gravity, chemical composition, planetary magnetic field, solar radiation, planetary rotation etc. The core of the planet does not play a major role as a variable in atmosphere.
8. The gas which is the most abundant component in the atmosphere of Venus is _____
a) Sulphur oxide
b) Oxygen
c) Carbon dioxide
d) Nitrogen
View Answer
Explanation: Carbon dioxide comprises of 96% of the atmosphere on Venus. It also contains small traces of nitrogen & sulphur oxides. So, the most abundant gas in the atmosphere of Venus is Carbon dioxide gas. This makes the atmosphere more denser & hotter as compared to Earth.
9. Which of the following statement is incorrect about weather?
a) It is a local phenomenon which occurs only at low altitudes
b) It is regarded to be in a thermal equilibrium, with negligible external influences
c) It is under constant perturbation due to winds and two-phase non-equilibrium of water vapour & carbon dioxide vapour on Mars and Earth respectively
d) It has very little impact on mean thermodynamic properties of the atmospheres
View Answer
Explanation: Weather is a local phenomenon which occurs only at low altitudes of the atmosphere. At low altitudes, the atmosphere is assumed to be in thermal equilibrium & is not influenced by external factors like electromagnetism or chemical reactions. But it is constantly disturbed by horizontal winds and two-phase non-equilibrium due to water vapour on Earth & carbon dioxide vapour on Mars.
10. All atmospheric models of the planets focus upon _____
a) Horizontal & Vertical variations of thermodynamic properties
b) Vertical variations of thermodynamic properties only
c) Horizontal variations of thermodynamic properties only
d) Weather effects on thermodynamic properties only
View Answer
Explanation: Horizontal effects, caused by weather & planetary rotation, have negligible variation in thermodynamic properties as compared to the Vertical variations. The thermodynamic properties of the atmosphere vary greatly with the altitude from the surface of the planet. More the change in the altitude, more is the variation in properties. So, only vertical variations are considered in all planetary atmospheric models.
More MCQs on Planetary Atmosphere:
Sanfoundry Global Education & Learning Series – Spaceflight Mechanics.
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