Motions of the Earth Inclination of the Earth’s Axis MCQ Quiz - Objective Question with Answer for Motions of the Earth Inclination of the Earth’s Axis - Download Free PDF

The correct answer is Equatorial regions.

Key Points

• The Congo rainforest is situated in Central Africa and spans across several countries including the Democratic Republic of the Congo, Cameroon, and Gabon.
• The region is characterized by high humidity, consistent temperatures, and heavy rainfall throughout the year.
• This rainforest is the second-largest tropical rainforest in the world, after the Amazon.
• It is home to a diverse range of flora and fauna, many of which are endemic to the region.

Important Points

• The Congo rainforest plays a crucial role in regulating the global climate by absorbing carbon dioxide.
• This region is facing significant threats from deforestation, logging, and mining activities.
• Conservation efforts are underway to protect this vital ecosystem and its biodiversity.

The correct answer is Equator.

Key Points

• The Equator is an imaginary line that divides the Earth into the Northern and Southern Hemispheres.
• It is designated as 0º latitude and runs horizontally around the globe.
• The Equator is the longest line of latitude, measuring approximately 40,075 kilometers in length.
• Regions along the Equator experience relatively constant temperatures and are generally characterized by tropical climates.

Additional Information

• Latitude: Latitude lines are imaginary horizontal lines that measure the distance of a location north or south of the Equator. They range from 0º at the Equator to 90º at the poles.
• Longitude: Longitude lines are vertical imaginary lines that measure the distance of a location east or west of the Prime Meridian. They converge at the poles and are measured in degrees (º).
• Greenwich: Greenwich refers to the Prime Meridian, which is the 0º longitude line passing through Greenwich, London. It is used as the reference point for measuring longitudes worldwide.

The correct answer is option 3.

Key Points

• Statement 1 – Correct – During an equinox (March 21 & Sept 23), day and night are nearly equal at all latitudes because the Sun is directly overhead at the equator.
• Statement 2 – Incorrect – On the Winter Solstice (December 21/22), the North Pole is in complete darkness (polar night), not daylight. Hence, Statement 2 is incorrect.
• Statement 3 – Correct – On an equinox, the Sun rises exactly in the east and sets exactly in the west for all locations, because Earth's axial tilt is neither away from nor toward the Sun.
  • Correct Answer: (c) 1 and 3 statements are correct.

The correct answer is Mantle.

Key Points

• The Mantle makes up about 84% of Earth's volume.
• The Mantle extends from the crust to the outer core.
• It is composed mainly of silicate minerals rich in iron and magnesium.
• The Mantle can be divided into the upper mantle and the lower mantle, separated by a transition zone.

Additional Information

• Crust
  • The Earth's crust is the outermost layer, making up less than 1% of Earth's volume.
  • It is composed of a variety of rocks and minerals and is divided into continental and oceanic crust.
• Inner Core
  • The inner core is a solid sphere composed mainly of iron and nickel.
  • It is the hottest part of the Earth and has a radius of about 1,220 kilometers.
• Outer Core
  • The outer core is a fluid layer composed mainly of iron and nickel.
  • It lies above the inner core and below the mantle and generates Earth's magnetic field through its convective movements.

The correct answer is Aryabhatta.

Key Points

• Aryabhatta
  • He wrote Aryabhatiya and Surya Siddhanta.
  • In Aryabhatiya, he wrote about Arithmetic, Geometry, Algebra, and Trigonometry. 
  • In the first chapter of the Aryabhatiya, he insisted that the earth rotates about its axis and that the apparent movement of the stars is a relative motion caused by the rotation of the earth. Hence, Option 1 is correct.
  • He gives the number of rotations of the earth in a yuga.
  • In Surya Siddhanta, he explained scientifically the causes of the solar and lunar eclipses.
  • Aryabhatta also founded the place value system and zero.

Additional Information

• ​Varahamihira 
  • ​He was an Indian astrologer and polymath. 
  • He discovered a version of Pascal's triangle and worked on magic squares.
  • He also improved the accuracy of the sine tables of Aryabhata.
• Bhaskara 
  • He is also known as Bhaskara I.
  • He was a known mathematician and astronomer and was born in India in the 7th century.
  • He contributed majorly in Mathematics and was the first to write numbers in the Hindu decimal system with a circle for the zero.
  • He also gave a unique and remarkable rational approximation of the sine function in his commentary on Aryabhata's work.
  • Bhaskara was honoured by the Indian Space Research Organisation by launching Bhaskara I on 7 June 1979.
• Brahmagupta
  • He was an Indian mathematician and astronomer.
  • He is the author of two early works on mathematics and astronomy: the Brāhmasphuṭasiddhānta, a theoretical treatise, and the Khaṇḍakhādyaka, a more practical text. Brahmagupta was the first to give rules to compute with zero. 

The correct answer is 21 June.

Key Points

• The longest day in the year is 21 June which is generally termed Summer Solstice.
• The summer solstice which is generally termed as an estival solstice or midsummer occurs when one of the Earth's poles has its maximum tilt toward the Sun.
• It happens twice annually, once in each hemisphere (Northern and Southern).
• For that hemisphere, the summer solstice is when the Sun reaches its apex position in the sky and is the day with the longest period of daylight.
• Within the Arctic Circle (for the northern hemisphere) or Antarctic Circle (for the southern hemisphere), there is incessant daylight around the summer solstice.
• On the summer solstice, the earth's maximum axial tilt toward the Sun is 23.44°.

Additional Information

• In addition to, the Sun's declination from the celestial equator is 23.44°.
• The summer solstice occurs during the summer period.
• This is the June solstice in the Northern Hemisphere and the December solstice in the Southern Hemisphere.
• Depending on the shift of the calendar, the summer solstice happens sometime between June 20 and June 22 in the Northern Hemisphere and between December 20 and December 23 in the Southern Hemisphere.
• The same dates on the contrary hemisphere are referred to as the winter solstice.

The correct answer is Earth’s revolution and inclination of its axis.

Key Points

• Seasons change because of the tilt of the Earth and the planet's movement around the Sun.
  •  Earth’s axis is not vertical. It’s actually tilted at an angle of 23.5°.
• Throughout the year, different parts of Earth receive the Sun's most direct rays.
  • When the North Pole tilts toward the Sun, it's summer in the Northern Hemisphere.
  • When the South Pole tilts toward the Sun, it's winter in the Northern Hemisphere.

Additional Information

• Near the Equator, days are always about 12 hours long. But these areas usually have a wet season and a dry season.

The correct answer is 21 March.

• Direct rays of the Sun fall on the equator on 21 March.

Key Points

• Every year on 21st March and September 23rd, direct rays of the sun fall on the equator.
• On these days neither of the earth's poles are tilted towards the sun hence, the whole earth experiences equal days and equal nights.
  • This is called an equinox.

Additional Information

• The Tropic of Capricorn receives direct rays of the sun on 22nd December, as the South Pole tilts towards it. 
• The longest day in the northern hemisphere occurs on 21st June.
  • This position of the earth is called the Summer Solstice.

The correct answer is 'Coriolis force'

Key Points

• Coriolis force:
  • The Coriolis force is an apparent force caused by the Earth's rotation.
  • It acts perpendicular to the direction of motion and the axis of rotation.
  • In the Northern Hemisphere, it causes moving objects to deflect to the right, and in the Southern Hemisphere, it causes deflection to the left.
  • This force significantly influences atmospheric and oceanic circulation patterns, such as trade winds, cyclones, and ocean currents.

Additional Information

• Kinetic Force:
  • Kinetic force refers to the force associated with the motion of an object.
  • It is not related to the Earth's rotation but rather to the energy an object possesses due to its motion.
• Pressure Prevalence:
  • Pressure prevalence is not a standard term in physics or Earth sciences.
  • It might refer to atmospheric pressure, but it does not describe a force caused by the Earth's rotation.
• Gravitational Force:
  • Gravitational force is the attraction between two masses.
  • While it is a fundamental force affecting all objects on Earth, it is not specifically generated by the Earth's rotation.
  • Gravitational force is responsible for keeping objects grounded on Earth and for the orbits of celestial bodies.

The correct answer is Revolution.

Key Points

• The movement of the earth
  • The earth has two types of motions, namely rotation, and revolution.
  • Rotation is the movement of the earth on its axis.
  • The movement of the earth around the sun in a fixed path or orbit is called Revolution. Hence, Option 2 is correct.
  • The axis of the earth which is an imaginary line makes an angle of 66½° with its orbital plane.
  • The plane formed by the orbit is known as the orbital plane. The earth receives light from the sun. Due to the spherical shape of the earth, only half of it gets light from the sun at a time.
  • The portion facing the sun experiences day while the other half away from the sun experiences night.
  • The circle that divides the day from night on the globe is called the circle of illumination. This circle does not coincide with the axis. The earth takes about 24 hours to complete one rotation around its axis.
  • The period of rotation is known as the Earthday.
  • The second motion of the earth around the sun in its orbit is called revolution.
  • It takes 365¼ days (one year) to revolve around the sun.
  • We consider a year as consisting of 365 days only and ignore six hours for the sake of convenience.
  • Six hours saved every year are added to make one day (24 hours) over a span of four years. This surplus day is added to February. Thus every fourth year, February is of 29 days instead of 28 days. Such a year with 366 days is called a leap year.
  • The earth is going around the sun in an elliptical orbit. Notice that throughout its orbit, the earth is inclined in the same direction.
  • A year is usually divided into summer, winter, spring, and autumn seasons. Seasons change due to the change in the position of the earth around the sun.

The correct answer is January 3.

• Perihelion is the point when Earth is closest to Sun and it occurs around 3rd January. The distance is 147.5 million km.
• Earth travels 939,886,400 km along its elliptical orbit in a single revolution.
• The average distance is 150 million km, but the orbit is elliptical and there is the difference if 2.5 million km.

Important Points

• On about July 4th earth is Farthest from Sun and this is called Aphelion. 
• Speed of Earth is fastest at Perihelion and slowest at Aphelion.
• The words come from Ancient Greek, in which helios means “Sun,” apo means “far,” and peri means “close.”
• Earth orbits the Sun in an elliptical path—which is oval, not circular.

The correct answer is 20 or 21 June.

Key Points

• Earth revolves around the sun in an elliptical orbit and throughout the orbit, it is inclined \(66{1 \over2}\)° to the plane of orbit.
• This results in changes of seasons on the earth due to changes in the position of the earth around the sun.
• On 21st June, the Northern Hemisphere is tilted towards the
  sun.
• The rays of the sun fall directly on the Tropic of Cancer. As a result, these areas receive more heat.
• The areas near the poles receive less heat as the rays of the sun are slanting.
• The North Pole is inclined towards the sun and the places beyond the Arctic Circle experience continuous daylight for about six months.
• Since a large portion of the Northern Hemisphere is getting light from the sun, it is summer in the regions north of the equator.
• The longest day and the shortest night at these places occur on 21st June.
• At this time in the Southern Hemisphere, all these conditions are reversed. It is winter season there. The nights are longer than the days.
• This position of the earth is called the Summer Solstice.

​

Additional Information

• Winter Solstice-
  • On 22nd December, the Tropic of Capricorn receives direct rays of the sun as the South Pole tilts towards it.
  • As the sun’s rays fall vertically at the Tropic of Capricorn (23­° S), a larger portion of the Southern Hemisphere gets light.
  • Therefore, it is summer in the Southern Hemisphere with longer days and shorter nights.
  • The reverse happens in the Northern Hemisphere. This position of the earth is called the Winter Solstice.
• Equinox-
  • On 21st March and September 23rd, direct rays of the sun fall on the equator.
  • At this position, neither of the poles is tilted towards the sun; so, the whole earth experiences equal days and equal nights. This is called an equinox.
  • On 23rd September, it is the autumnal equinox in the Northern Hemisphere and the vernal equinox in the Southern Hemisphere.
  • The opposite is the case on 21st March when it is the vernal equinox in the Northern Hemisphere and the autumnal equinox in the Southern Hemisphere.​

The correct answer is 23 1/2^o  in the Southern Hemisphere.

Key Points

• 23 1/2^o in the Southern Hemisphere parallels of latitude represent the Tropic of Capricorn.
• The Tropic of Capricorn (or the Southern Tropic) is the circle of latitude that contains the subsolar point at the December (or southern) solstice.

• It is thus the southernmost latitude where the Sun can be seen directly overhead.
• It also reaches 90 degrees below the horizon at solar midnight on the June Solstice.
• Its northern equivalent is the Tropic of Cancer.
• The Tropic of Capricorn is one of the five major circles of latitude marked on maps of Earth.
• Its latitude is currently 23°26′11.1″ (or 23.43641°) south of the Equator, but it is very gradually moving northward, currently at the rate of 0.47 arcseconds, or 15 meters, per year.
• Less than 3% of the world's population lives south of it; this is equivalent to about 30% of the population of the Southern Hemisphere.

Additional Information

• The latitude is the angle formed by a line going from the center of the earth to the equator at the point on the equator that is closed to the point of interest and another line that goes from the center of the earth to the parallel that goes through the point of interest.
  • Latitude is a measurement on a globe or map of location north or south of the Equator.
  • Lines joining places with the same latitudes are called parallels ie the lines running East to West are called “Parallels” or “lines of latitude”.
  • Technically, there are different kinds of latitude—geocentric, astronomical, and geographic (or geodetic)—but there are only minor differences between them.
  • In most common references, geocentric latitude is implied.
  • Given in degrees, minutes, and seconds, geocentric latitude is the arc subtended by an angle at Earth’s centre and measured in a north-south plane poleward from the Equator.
  • Therefore, the greatest possible latitudes are 90° N and 90° S.
• Important parallels of latitude:
  • The equator
  • The Tropic of Cancer (23½ºN)
  • The Tropic of Capricorn (23½ºS)
  • The Arctic Circle (66½ºN)
  • The Antarctic Circle (66½ºS)

The correct answer is 21st March.

Key Points

• Equinox
  • On 21st March and September 23rd, direct rays of the sun fall on the equator. Hence, Option 1 is correct.
  • At this position, neither of the poles is tilted towards the sun; so, the whole earth experiences equal days and equal nights. This is called an equinox.
  • On 23rd September, it is autumn season in the Northern Hemisphere and spring season in the Southern Hemisphere.
  • The opposite is the case on 21st March when it is spring in the Northern Hemisphere and autumn in the Southern Hemisphere.
  • Thus, there are days and nights and changes in the seasons because of the rotation and revolution of the earth respectively.
  • The word equinox is derived from two Latin words – aequus (equal) and nox (night).
  • There are only two times of the year when the Earth’s axis is tilted neither toward nor away from the sun, which results in a nearly equal amount of daylight and darkness at all latitudes. These events are referred to as Equinoxes.
  • The equinoxes happen in March (about March 21) and September (about September 23) on these days the Sun is exactly above the Equator
  • The equator and places near the equator experience nearly 12 hours of the day and 12 hours of the night.
  • The phenomenon occurs due to the Earth’s axial tilt, or the angle by which the planet is tilted relative to the Sun. 
  • The imaginary axis of our planet is not straight up and down but is tilted by 23.5 degrees. 
  • This is why different regions of the Earth experience different measures of sunlight.
  • The days become a little longer at the higher latitudes (those at a distance from the equator) because it takes the sun longer to rise and set.  
  • The solstices, together with the equinoxes, are connected with seasons, harvests, and livelihood.
  • Therefore, many cultures celebrate various combinations of the solstices, the equinoxes, and the midpoints between them, leading to various holidays arising around these events.

The correct answer is Seven.

• The seven brightest stars in the constellation are called the Great Bear.

Key Points

• Ursa Major constellation lies in the northern sky. Its name means the great bear, or the larger bear, in Latin. The smaller bear is represented by Ursa Minor.
• Ursa Major is the largest northern constellation and the third largest constellation in the sky. Its brightest stars form the Big Dipper asterism, one of the most recognizable shapes in the sky, also known as the Plough.
• Ursa Major is well-known in most world cultures and associated with a number of myths. It was one of the constellations catalogued by the Greek astronomer Ptolemy in the 2nd century.
• Ursa Major contains a number of notable stars and famous deep-sky objects. These include the Pinwheel Galaxy (M101), Bode’s Galaxy, the Cigar Galaxy, and the Owl Nebula.

Additional Information

• Ursa Major constellation map:  

Important Points

• The biggest known galaxy is IC 1101, which is 50 times the Milky Way's size and about 2,000 times more massive.
  • It is about 5.5 million light-years across. 
• Our Sun (a star) and all the planets around it are part of a galaxy known as the Milky Way Galaxy.
  • A galaxy is a large group of stars, gas, and dust bound together by gravity. The Milky Way is made up of about 90% dark matter, the matter which cannot be seen, and about 10% luminous matter, or matter that we can see with our eyes.
  • The solar system lies about 30,000 light-years from the galactic centre.