Geography · Physics

Geodesy and Celestial Mechanics

984 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 properties of a magnetic field earth - a gigantic magnet magnetic field of earth introduction to magnetic field and magnetic flux

The angle of declination at a place is the angle

  1. Between the vertical plane and the geographical meridian

  2. Between the vertical plane and the magnetic meridian

  3. Between the geographical meridian and magnetic meridian

  4. Between the geographical meridian and horizontal plane
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A freely suspended magnet always points in the North-South direction even in the absence of any other magnet. This suggests that the Earth itself behaves as a magnet which causes a freely suspended magnet (or magnetic needle) to point always in a particular direction: North and South.

The vertical plane passing through the axis of a freely suspended magnet is called magnetic meridian. The direction of Earth's magnetic field lies in the magnetic meridian and may not be horizontal. The vertical plane passing through the true geographical North and South (or geographical axis of Earth) is called geographical meridian. The angle between the magnetic meridian and the geographic meridian at a place is called declination at that place.

Multiple choice physics properties of a magnetic field earth - a gigantic magnet magnetic field of earth introduction to magnetic field and magnetic flux

The bulging of earth at the equator and flattening at the poles is due to 

  1. Centripetal force

  2. Centrifugal force

  3. Gravitational force

  4. Electrostatic force
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The bulging of equator and flattening at poles is due to rotation of earth. The rotation of earth creates a centrifugal force which is pseudo effect counter balancing the inward acting centripetal force. This pseudo effect pushes the earth outward, bugling from earth, and flattening at poles. 

Hence correct answer is option B.

Multiple choice physics properties of a magnetic field earth - a gigantic magnet magnetic field of earth introduction to magnetic field and magnetic flux

Define angle of declination at a place :

  1. angle between the vertical plane and the geographical meridian

  2. angle between the vertical plane and the magnetic meridian

  3. angle between the geographical meridian and the magnetic meridian

  4. angle between the geographical meridian and horizontal plane
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The magnetic meridian is an equivalent imaginary line connecting the magnetic south and north poles and can be taken as the magnetic force lines along the surface of the earth. Therefore a compass needle will be parallel to the magnetic meridian.

The angle between the magnetic and the true meridian is the angle of declination, which is relevant for navigating with a compass.

Multiple choice physics properties of a magnetic field earth - a gigantic magnet magnetic field of earth introduction to magnetic field and magnetic flux

The north pole of earth's magnet is near __________.

  1. geographic north

  2. the centre of earth

  3. geographic south

  4. Both (A) and (C)
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The opposite poles of two magnets attract.
So, north pole of earth's magnet is near the geographic south. The magnetic field created by the molten core of the earth have a magnetic south pole near the geographic north pole to attract N-pole.
Hence, option : C.
Multiple choice physics properties of a magnetic field earth - a gigantic magnet magnetic field of earth introduction to magnetic field and magnetic flux

The actual north magnetic pole of earth

  1. Is situated near the geographic south pole.

  2. Is north pole of the magnetic substance of the earth's core.
  3. Attracts the $N$ pole of the compass needle.
  4. Both $(1)$ and $(2)$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The reason for the magnetic field of the earth is the magnetic substance in the earth’s core. 

So the pole of the earth is the pole of the magnetic substance in the earth’s core.

The actual north magnetic pole of earth is situated near the geographic south pole because the unlike poles attract each other.

 

Multiple choice physics properties of a magnetic field earth - a gigantic magnet magnetic field of earth introduction to magnetic field and magnetic flux

The place where the angle of dip is 90 are known as

  1. Geographical poles of the earth

  2. Magnetic equator

  3. Magnetic poles of the earth

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Angle of dip at a point on earth is the angle between earth's magnetic field at given point and the horizontal line of magnetic meridian.

Since the magnetic lines of force emerge and terminate at the poles of Earth, the magnetic lines of force at the poles are perpendicular to the surface there. Hence the angle of dip is $90^{\circ}$.

Multiple choice physics properties of a magnetic field earth - a gigantic magnet magnetic field of earth introduction to magnetic field and magnetic flux

The north pole of earth's magnet is near

  1. Geographic north

  2. At the center of earth

  3. Geographic south

  4. In any direction
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Keep this well in mind that the magnetic poles are opposite in position as the geographic poles.

Magnetic north is at geographic south and vice versa.
Geographic north is the part which includes Greenland and south is Antartica.
When we hang a bar magnet then its poles are attracted to the opposite magnetic poles of the earth. We know that opposite poles attract each other.
That's the reason why the bar's north pole turns towards the geographic north of the earth and the south to south.

Multiple choice physics properties of a magnetic field earth - a gigantic magnet magnetic field of earth introduction to magnetic field and magnetic flux

The earth's field departs from its dipole shape substantially at large distance (greater than about $3000$ km). The responsible factor for this distortion is then

  1. motion of ions in earth's ionosphere

  2. motion of ions in earth's atmosphere

  3. motion of ions in earth's lithosphere

  4. motion of ions in the space.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Due to motion of ions in earth's ionosphere the earth's magnetic field gets modified.

Multiple choice geography our changing earth earthquake earthquakes earth's movement and creation of landforms

The axis of rotation of the earth is __________.

  1. Vertical

  2. Horizontal

  3. Tilted

  4. Both A and B
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

1;The earth rotates around its vertical axis. The axis is an imaginary line passing through the centre of the earth. Its two ends on the surface are called North and South poles The Earth completes one rotation in 24 hours. 

2:The Earth's axis is vertical, meaning it runs up and down. (A rolling log, on the other hand, has a horizontal axis, meaning it runs sideways.) The Earth's axis runs from the North Pole to the South Pole. It takes the Earth 24 hours, or one day, to make one complete rotation around this invisible line

Multiple choice geography the signature of time movement of the earth's plates development of landforms study of continents - north america

The tilt of the earth's axis does not affect the variations in season at _______.

  1. The equator

  2. North pole

  3. South pole

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

 At the equator there are no seasons because each day the Sun strikes at about the same angle. Every day of the year the equator receives about 12 hours of sunlight.

Multiple choice commercial applications issues of the environment excessive consumption of resources atmosphere and its components atmosphere- wind

Where are the days and nights of equal length all year long?

  1. At $66.5^{o}$

  2. Nowhere
  3. At $23.5^{o}$

  4. At the Equator
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The Equator receives approximately equal day and night lengths throughout the year because it is positioned such that the sun's path remains consistent relative to the horizon.

Multiple choice commercial applications issues of the environment excessive consumption of resources atmosphere and its components atmosphere- wind

At which latitude heat gain through insolation approximately equals heat loss through terrestrial radiation:

  1. $22.5^0$ North and South
  2. $40^0$ North and South
  3. $42.5^0$ North and South
  4. $66^0$ North and South
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Heat gain from solar insolation approximately balances heat loss from terrestrial radiation around the 40 degree latitude lines in both the Northern and Southern Hemispheres. Lower latitudes receive a net surplus of energy, while higher latitudes experience a net deficit.