Geography · Physics

Geodesy and Celestial Mechanics

1,049 Questions

Geodesy and celestial mechanics questions explore Earth measurements, great circles, and planetary motions. These concepts form a crucial part of physical geography and astronomy in competitive exams. Practice these questions to grasp longitudinal and latitudinal calculations.

Longitude and latitude calculationsGreat circle conceptEarths axial precessionLagrangian pointsAtmosphere boundary

Geodesy and Celestial Mechanics Questions

Multiple choice evs artificial satellite types of artificial satellites geostationary orbits moon and stars in sky

The distance of the moon from the earth is about 60 times the radius of the earth. What will be diameter of the earth (approximately in degrees) as seen from the moon.?

  1. $1^o$.
  2. $2^o$.
  3. $4^o$.
  4. $6^o$.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

From figure
We know the formula 

$\theta=\dfrac{Diameter \ of \ earth}{R}$

$\displaystyle \theta = \frac{2R _E}{60 R _E}$

$= \dfrac{1}{30} rad = \dfrac{1}{30} \times \dfrac{180^o}{\pi} = 2^o$

The diameter of the earth as seen from the moon is about $2^o$.
Multiple choice evs artificial satellite types of artificial satellites geostationary orbits moon and stars in sky

A satellite launching station should be

  1. near the equatorial region.

  2. near the polar region.

  3. on the polar axis.

  4. all locations are equally good.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
At equator, $g$ is minimum relative to all the other points on the surface of the Earth. When a spacecraft is launched into the orbit, it should end up spinning around the Earth quickly enough not to be pulled back in by the Earth's gravity. If a ship is launched from the equator, it goes up into space, and it is also moving around the Earth at the same speed it was moving before launching. This is because of inertia. This speed will help the spacecraft keep up a good enough speed to stay in the orbit.
Multiple choice evs artificial satellite types of artificial satellites geostationary orbits moon and stars in sky

The minimum number of satellites needed to be placed for world-wide communication between any two locations on earth's surface  is:

  1. 6

  2. 4

  3. 3

  4. 5
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

For a world-wide communication between any two locations of the earth, minimum 3 satellites must be placed such that each pair of  the satellites subtend angle of $120^o$ at the centre of earth. 

Multiple choice evs artificial satellite types of artificial satellites geostationary orbits moon and stars in sky

Height of geostationary satellite is

  1. $16000km$
  2. $22000km$
  3. $28000km$
  4. $36000km$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$Answer:-$ D

Approximately $35,786$ km.
A geostationary equatorial orbit (GEO) is a circular geosynchronous orbit in the plane of the Earth's equator with a radius of approximately $42,164$ km ($26,199$ mi) (measured from the center of the Earth). A satellite in such an orbit is at an altitude ofapproximately $35,786$ km ($22,236$ mi) above mean sea level.
Multiple choice evs artificial satellite types of artificial satellites geostationary orbits moon and stars in sky

Imagine a geostationary satellite of earth which is used as an inter continental telecast station. At what height will it have to be established?

  1. at $10^{3}m$
  2. at $6.4\times 10^{3}m$
  3. at $35.94\times 10^{6}m$

  4. at infinity
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Time period for a geostationary satellite is 24 hour, so $t=24$

And $t=2\pi \sqrt{\dfrac{(R+h)^2}{GM}}$
So, $h=35.94\times 10^6m$

Multiple choice geography europe - location, political divisions and physical features mediterranean climatic region location, political and physical divisions of europe environmental regions

The latitudinal extent of Europe is ________.

  1. $36^0 N to 72^0 N$
  2. $39^0 N to 72^0 N$
  3. $38^0 N to 72^0 N$
  4. $37^0 N to 72^0 N$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

State the latitudinal and longitudinal extent of Europe. Answer: Europe lies between the latitudes 35°N to 72°N and the longitudes 25°W to 65°E.

Multiple choice evs - i the earth and its living world introduction to the spheres of the earth origin of universe introduction to natural resources

The thickness of troposphere is

  1. 12 km

  2. 40km

  3. 8o km

  4. 50 km
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The atmosphere is made up of five layers mainly, exosphere, thermosphere, mesosphere, stratosphere and troposphere. The thickness of troposphere is measured 12 km. The tropopause is the boundary region between the troposphere and the stratosphere. It is the lowest major atmospheric layer, extending from the Earth's surface up to the bottom of the stratosphere. 
So, the correct answer is option A.
Multiple choice evs - i the earth and its living world introduction to the spheres of the earth origin of universe introduction to natural resources

Lapse rate in troposphere is

  1. $3.1^0$ C/km
  2. $6.5^0$ C/km
  3. $9.8^0$ C/km
  4. $13.6^0 C/km
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Troposphere is the lowest layer in the earth's atmosphere. it is the same layer in which all the change in weather takes place. Lapse rate is the rate at which the temperature drops due to the difference in elevation. the more the altitude the more the drop in temperature is there. The lapse rate of $6.5$ is there for the level of $0$ to  $11,000$ m. This is the region in which troposphere lies. 

So, the correct answer is ' $6.5^oC$$/Km$. '

Multiple choice evs - i the earth and its living world introduction to the spheres of the earth origin of universe introduction to natural resources

Ozonosphere occurs at a height of 

  1. 8-10 km above poles

  2. 8-10 km above equator

  3. 12-20 km above poles

  4. 11-16 km above equator
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The ozone layer (ozonosphere) is generally found at altitudes of 15-35 km. The options provided are confusingly phrased regarding poles versus equator, but 12-20 km is a common range for the lower boundary of the ozone layer.

Multiple choice evs - i the earth and its living world introduction to the spheres of the earth origin of universe introduction to natural resources

71% of earth is covered by

  1. Biosphere

  2. Lithosphere

  3. Atmosphere

  4. Hydrosphere
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

a) The biosphere is the sum of all ecosystem. It is the layer of earth where life exists.

b) The lithosphere is the outer part of the earth, consisting of the crust and upper mantle.
c) The atmosphere is the layer of gases which surrounds the earth.
d) The water present on earth in form of lakes, oceans, rivers, etc is called hydrosphere. About 2/3rd (71%)of earth's crust is covered by water. water also exists in form of water vapour in the air. The water is recycled from the surface of the earth to the atmosphere and back to the earth surface by the process of the water cycle. It supports the life across the earth.
So, the correct answer is option D.

Multiple choice commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

Ozonosphere occurs at height of

  1. 8-10 km. above poles

  2. 8-10 km. above equator

  3. 11-16 km above poles

  4. 11=-16 km above equator
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The ozone layer (ozonosphere) is generally found in the stratosphere. Its altitude varies, being lower at the poles (around 11-16 km) and higher at the equator.