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 physics measurements and experimentation measuring distance of celestial bodies unconventional units of measurements units of mass

One light year is used for measurement of large distances?

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
One light year is defined as the distance travelled by light in one year in vacuum.
$1 \ light  \ year = 9.5\times 10^{15} \ m$
Since, one light year is very large value. Thus one light year is used for measurement of large distance.
Multiple choice physics units and measurement: error analysis rounding off digits rounding of digits standard form
The Earth's radius is $6371km$. The order magnitude of the Earth's radius is
  1. $10^3$
  2. $10^2$
  3. $10^7$
  4. $10^5$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Order of magnitude is usually written as $10 $ to the $n$th power. The represents the order of magnitude.
e.g., if we write a number $X$ in such a way that
$X = m × 10^n$ then n is order of magnitude.
here, $6371 km = 6371000 m$
$6371000 = 6.371 × 10^6$
we see, $ 6.371 ≥ \sqrt{10}$
so, $0.6371 × 10^7$
, $\dfrac{\sqrt{10}}{\sqrt{10}} ≤ 0.6371 ≤ √10$
7 is our order of magnitude.
Multiple choice physics units and measurement: error analysis rounding off digits rounding of digits standard form

The radius of the earth is given $6.4\times 10^6 m$. What is the order of magnitude of the size of the earth? 

  1. $10^6 m$
  2. $6 \times 10^6 m$
  3. $10^7 m$
  4. $5 \times 10^6 m$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When a number rounded to the nearest power of 10, it is called order of magnitude. Here a number which is less than 5 is taken as 1 and a number greater than 5 is taken as 10. 
As $6.4>10, $ so it would be takes as 10. 
The order of magnitude of earth's size $=10\times 10^6=10^7 m$  

Multiple choice physics units and measurement: error analysis rounding off digits rounding of digits standard form

What is the order of magnitude of the distance of a quasar from us if light takes 2.9 billion years to reach us ?  

  1. $2.7\times 10^{25} m$
  2. $ 10^{25} m$
  3. $10^24 m$
  4. $3\times 10^{25} m$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Here, time taken $t=2.9$ billion years $=2.9\times 10^9$ years $ =2.9\times 10^9\times (365\times 24\times 3600) s=9.14\times 10^{16} s$
Distance $=$ velocity $\times $ time
or $d=(3\times 10^8)\times (9.14\times 10^{16})=2.74\times 10^{25} m$
As $2.74 <5$ so it will be taken as 1. 
Thus, the order of magnitude of distance $d=1\times 10^{25} m=10^{25} m$

Multiple choice

Earth's four major spheres are the ____

  1. hydrosphere, geosphere, lithosphere, asthenosphere

  2. hydrosphere, asthenosphere, lithosphere, biosphere

  3. hydrosphere, atmosphere, geosphere, biosphere

  4. hydrosphere, atmosphere, lithosphere, biosphere
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Earth's four major spheres are the hydrosphere (water), atmosphere (air), geosphere (land/rock), and biosphere (living things).

Multiple choice

How far away is the center of our galaxy?

  1. 25,000-26,000 feet

  2. 25,000-26,000 miles

  3. 25,000-26,000 light years

  4. at the edge of our solar system
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The center of the Milky Way galaxy is approximately 25,000 to 26,000 light years away from Earth. Feet and miles are units of distance too small for galactic scales.

Multiple choice

How far is Jupiter from the Sun?

  1. 484 000 000

  2. 1 000 000

  3. 2 799 000 000

  4. 600
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Jupiter is approximately 484 million miles from the Sun. The other options represent incorrect distances.

Multiple choice stefan's law black body radiation heat transfer thermal properties physics

The solar constant for the earth is $\Sigma$. The surface temperature of the sun is $T$ K. The sun subtends an angle $\theta$ at the earth

  1. $\Sigma \space \propto \space T^4$
  2. $\Sigma \space \propto \space T^2$
  3. $\Sigma \space \propto \space \theta^4$
  4. $\Sigma \space \propto \space \theta$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

By Stephan Boltzman law,


$P=\sigma (4\pi { R }^{ 2 }){ T }^{ 4 }$

$\theta =\dfrac { 2r }{ R } $ where R is distance between earth and sun and r is radius of earth.

Hence, $\sum {  } =\dfrac { P }{ 4\pi { r }^{ 2 } } =C{ T }^{ 4 }{ \left( \dfrac { R }{ r }  \right)  }^{ 2 }=K{ T }^{ 4 }{ \theta  }^{ 2 }$

Hence $\sum {  } \alpha { T }^{ 4 }$ and $\sum {  } \alpha { \theta }^{ 2 }$

Answer is option A.

Multiple choice evs - i sources of water the lithosphere and the hydrosphere first aid safety and first aid

Total earth's surface covered by water is

  1. 71%

  2. 60%

  3. 85%

  4. 50%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

71% of earth's surface is covered with water and 29% covered with land. This percentage of water is not only obvious sources of water like lakes, ponds, oceans but also the obvious sources of water like water in the air, frozen icecaps, glaciers, snow and underground water.

Therefore, the correct answer is option A.