Solar System — BSSC Geography

Sample Questions from this Test

Question 1:

Which planet has the longest day in the solar system, taking more time to complete one rotation than one revolution?

A.Jupiter

B.Venus

C.Neptune

D.Mars

• Venus rotates very slowly, making its day (243 Earth days) longer than its year (225 Earth days).

• It also rotates in the opposite direction (retrograde) to most planets, so the Sun rises in the west.

• Earth's rotation period is 23 hours 56 minutes, which makes an Earth day.

• Jupiter has the fastest rotation (~9.9 hours), Mars has a similar day to Earth (24.6 hours), and Neptune takes ~16 hours.

• Remember Venus as the 'lazy backward' planet—slowest rotation and retrograde.

• Venus is the hottest planet due to a runaway greenhouse effect from its 96.5% carbon dioxide atmosphere.

Question 2:

Consider the following statements regarding planetary atmospheres:

1. Venus has thick clouds of sulfuric acid in its atmosphere.

2. Mars’ atmosphere is mainly composed of methane.

3. Uranus has a blue-green colour due to the absorption of red light by methane.

A.1 and 2 only

B.2 and 3 only

C.1 and 3 only

D.All of the above

• Venus indeed has clouds of sulfuric acid, and Uranus appears blue-green because of methane.

• Statement 2 is incorrect because Mars' atmosphere is 95.32% Carbon Dioxide, not mainly methane.

• Uranus and Neptune both owe their blue hues to methane in their atmospheres.

• Any option including Statement 2 is wrong because Mars is CO2 dominated.

• 'Uranus = Methane = Blue/Green'. 'Venus = CO2 + Sulfuric Acid = Hottest'.

• The surface pressure of Mars is only 610 Pascals, and its gravity is about one-third of Earth's.

Question 3:

Assertion (A): Saturn would theoretically float if there were a body of water large enough to hold it.

Reason (R): Saturn is a gas giant primarily composed of hydrogen and helium, and its density is less than that of water.

A.Both A and R are true, and R is the correct explanation of A

B.Both A and R are true, but R is NOT the correct explanation of A

C.A is true but R is false

D.A is false but R is true

• Saturn's density is approximately 0.70 gm/cm³, which is lower than water's density (1 gm/cm³).

• Because its density is lower than water, it is the only planet that would float.

• Earth, by contrast, is the densest planet in the solar system (5.514 gm/cm³).

• Both statements are completely factually accurate and directly related.

• 'Saturn = 0.7 g/cm³ = Floats on water'.

• Saturn also has the most extensive ring system composed of ice, rock, and dust.

Question 4:

Arrange the following stages of the life cycle of a medium-sized star (like our Sun) in the correct chronological sequence:

1. Red Giant

2. White Dwarf

3. Nebula (Protostar)

4. Main Sequence

A.3 → 1 → 4 → 2

B.3 → 4 → 1 → 2

C.4 → 3 → 1 → 2

D.3 → 4 → 2 → 1

• The correct order is Nebula/Protostar → Main Sequence → Red Giant → White Dwarf.

• Stars are born in a nebula. They spend most of their life in the Main Sequence fusing hydrogen.

• When hydrogen is exhausted, it expands into a Red Giant, and eventually sheds layers to become a White Dwarf.

• Main sequence cannot come before Nebula, and White dwarf is the final remnant, not an intermediate stage.

• Remember the acronym NMRW (Nebula, Main, Red, White) for Sun-like stars.

• Heavier mass stars end up as Neutron Stars or Black Holes after a Supernova.

Question 5:

The "Faint Young Sun Paradox" challenges our understanding of early Earth because:

A.It implies early solar output was too weak to prevent global freezing, yet liquid water existed.

B.It proves that Earth was extremely hot due to excessive solar flares.

C.It suggests the Moon provided atmospheric heat to Earth.

D.It states that the Sun was originally a white dwarf.

• 4 billion years ago, the Sun's luminosity was only 70% of its current strength, which should have frozen Earth.

• Geological evidence shows liquid water existed, allowing life to evolve, creating a 'paradox'.

• Scientists believe early greenhouse gases must have compensated for the weaker Sun.

• The paradox is about a faint/weak sun, not a hot sun, white dwarf, or lunar heat.

• 'Faint = Weak'. Weak sun + liquid water on Earth = Paradox.

• The Sun generates energy through nuclear fusion (Hydrogen -> Helium) in its core.

Question 6:

Match the following hypothesis of Solar System formation with their proponents:

List I: a. Nebular Hypothesis, b. Planetesimal Hypothesis, c. Tidal Hypothesis, d. Expanding Universe Hypothesis

List II: 1. Thomas Chamberlin & Forest Moulton, 2. James Jeans & Harold Jeffreys, 3. Immanuel Kant, 4. Edwin Hubble

A.a-3, b-1, c-2, d-4

B.a-1, b-3, c-2, d-4

C.a-3, b-2, c-1, d-4

D.a-4, b-1, c-2, d-3

• Nebular: Kant. Planetesimal: Chamberlin & Moulton. Tidal: Jeans & Jeffreys. Expanding Universe: Hubble.

• Laplace later revised Kant's Nebular Hypothesis in 1796.

• The Expanding Universe hypothesis was proven by redshift in galaxy spectrums.

• Only combination A perfectly aligns the theories with their original authors as per the sources.

• 'Nebular = Kant/Laplace', 'Tidal = Jeans', 'Planetesimal = Chamberlin/Moulton'.

• Hubble's 1929 discovery showed galaxies moving away from each other.

Question 7:

Find the Odd One Out based on the presence of natural satellites (moons):

A.Earth

B.Mars

C.Mercury

D.Jupiter

• Mercury has zero natural satellites (moons).

• Earth has 1 (Moon), Mars has 2 (Phobos, Deimos), and Jupiter has many (95 known, including Galilean moons).

• Venus is the only other planet in our solar system that lacks a natural satellite.

• Earth, Mars, and Jupiter all have moons, making Mercury the odd one out.

• Mercury and Venus are the only two 'moonless' planets.

• Ganymede (Jupiter) is the largest moon in the solar system, bigger than the planet Mercury itself.

Question 8:

Which spacecraft was launched by NASA specifically to study the environment of Venus?

A.Juno Mission

B.Magellan Spacecraft

C.Cassini

D.Messenger Satellite

• The Magellan Spacecraft was launched by NASA in 1989 to study the environment of Venus.

• Juno was sent to Jupiter, Cassini to Saturn, and Messenger to Mercury.

• Venus is often called Earth's twin due to similar size and structure.

• The options correspond to different planets: Juno (Jupiter), Cassini (Saturn), Messenger (Mercury).

• 'Magellan = Venus', 'Messenger = Mercury', 'Juno = Jupiter', 'Cassini = Saturn'.

• The Hope orbiter was launched to Mars by the UAE in 2020.

Question 9:

Consider the following statements regarding eclipses:

1. A solar eclipse occurs on a full moon day.

2. A lunar eclipse occurs when Earth comes between the Sun and the Moon.

A.1 only

B.2 only

C.Both 1 and 2

D.Neither 1 nor 2

• A lunar eclipse happens when Earth is between the Sun and Moon, casting a shadow on the Moon (occurs on Full Moon).

• Statement 1 is incorrect because a solar eclipse occurs on a New Moon day (Amavasya), not a full moon.

• Lunar eclipses don't happen every full moon because the Moon's orbit is tilted 5 degrees relative to Earth's orbit.

• Solar eclipse = New Moon. Lunar eclipse = Full Moon.

• 'Solar = Sun hidden by Moon = New Moon'. 'Lunar = Moon hidden by Earth = Full Moon'.

• During a total solar eclipse, the Sun's outermost atmosphere, the Corona, becomes visible.

Question 10:

Who was the first astronomer to mathematically calculate and predict the location of the planet Neptune by studying gravity-induced disturbances in Uranus's orbit?

A.Galileo Galilei

B.William Herschel

C.Urbain-Jean-Joseph Le Verrier

D.Edwin Hubble

• Urbain Le Verrier calculated Neptune's approximate location based on gravitational disturbances in Uranus's motion.

• Neptune is the only planet in our solar system found by mathematical prediction rather than empirical observation.

• William Herschel discovered Uranus in 1781 using a telescope.

• Galileo observed Jupiter's moons, Herschel found Uranus, and Hubble discovered the expanding universe.

• 'Math prediction planet = Neptune = Le Verrier'.

• Neptune is the windiest planet in our solar system and takes 164.8 Earth years to orbit the Sun.

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