Part II — Questions 26–50

26. The Moon takes about how many days to revolve around the Earth (one lunar month)?
    A. 7 days
    B. 27–29.5 days (about 1 month)
    C. 365 days
    D. 1 day
    Correct Answer: B — 27–29.5 days (about 1 month)
    Explanations:
    A: Incorrect — 7 days is only a week.
    B: Correct — the Moon’s orbital period is ~27.3 days; synodic month (phase cycle) ~29.5 days.
    C: Incorrect — 365 days is Earth’s revolution period.
    D: Incorrect — 1 day is Earth’s rotation period.

27. Which planet is known for its very dense atmosphere and extreme greenhouse effect?
    A. Venus
    B. Mars
    C. Mercury
    D. Saturn
    Correct Answer: A — Venus
    Explanations:
    A: Correct — Venus has thick CO₂-rich atmosphere causing very high surface temperatures.
    B: Incorrect — Mars has a thin atmosphere.
    C: Incorrect — Mercury has almost no atmosphere.
    D: Incorrect — Saturn is a gas giant but not known for extreme greenhouse like Venus.

28. The tail of a comet always points:
    A. Toward the Sun
    B. Toward Earth
    C. Away from the Sun (pushed by solar wind)
    D. Toward the nearest planet
    Correct Answer: C — Away from the Sun (pushed by solar wind)
    Explanations:
    A: Incorrect — tails point away, not toward the Sun.
    B: Incorrect — tail direction depends on Sun, not Earth.
    C: Correct — solar radiation and solar wind push gas and dust away, forming tails directed away from the Sun.
    D: Incorrect — tail is not oriented toward planets.

29. Which planet has a system of faint rings (but not as visible as Saturn’s)?
    A. Venus
    B. Earth
    C. Neptune (and also Uranus and Jupiter have faint rings)
    D. Mars
    Correct Answer: C — Neptune (and also Uranus and Jupiter have faint rings)
    Explanations:
    A: Incorrect — Venus has no rings.
    B: Incorrect — Earth has no rings.
    C: Correct — Neptune, Uranus and Jupiter have faint ring systems; Saturn’s are the most prominent.
    D: Incorrect — Mars has no ring system (it has tiny moons).

30. The Milky Way is:
    A. A planet
    B. A galaxy containing billions of stars including the Sun
    C. A comet
    D. The Moon’s dust layer
    Correct Answer: B — A galaxy containing billions of stars including the Sun
    Explanations:
    A: Incorrect — Milky Way is vast, far larger than a planet.
    B: Correct — our solar system is in the Milky Way galaxy.
    C: Incorrect — a comet is much smaller.
    D: Incorrect — not related to Moon’s dust.

31. Which is the farthest planet from the Sun among the eight?
    A. Uranus
    B. Saturn
    C. Neptune
    D. Pluto (dwarf planet)
    Correct Answer: C — Neptune
    Explanations:
    A: Incorrect — Uranus is seventh from the Sun.
    B: Incorrect — Saturn is sixth.
    C: Correct — Neptune is the eighth and farthest major planet.
    D: Pluto is classified as a dwarf planet and varies in distance; not counted among eight planets.

32. The group of stars that contains the Sun is called the:
    A. Orion
    B. Milky Way
    C. Big Dipper
    D. Polaris group
    Correct Answer: B — Milky Way
    Explanations:
    A: Incorrect — Orion is a constellation, not the galaxy.
    B: Correct — the Sun and our solar system lie in the Milky Way galaxy.
    C: Incorrect — Big Dipper is an asterism within Ursa Major, not the galaxy.
    D: Incorrect — Polaris is a star, not a grouping containing the Sun.

33. Meteorites are:
    A. Small natural objects that burn completely in Earth’s atmosphere always
    B. Rocks from space that reach Earth’s surface (some survive the atmosphere)
    C. Artificial satellites that fall intentionally
    D. Exactly the same as a comet
    Correct Answer: B — Rocks from space that reach Earth’s surface (some survive the atmosphere)
    Explanations:
    A: Incorrect — meteors burn in atmosphere but meteorites are those fragments that survive to the ground.
    B: Correct — meteorites are space rocks found on Earth after entry.
    C: Incorrect — meteorites are natural, not man-made satellites.
    D: Incorrect — comets are icy bodies, different from meteorites.

34. The nearest star to Earth (other than the Sun) is:
    A. Sirius
    B. Proxima Centauri (part of Alpha Centauri system)
    C. Polaris
    D. Betelgeuse
    Correct Answer: B — Proxima Centauri (part of Alpha Centauri system)
    Explanations:
    A: Incorrect — Sirius is bright but not the closest.
    B: Correct — Proxima Centauri is the nearest known star to the Sun at ~4.24 light years.
    C: Incorrect — Polaris is much farther away.
    D: Incorrect — Betelgeuse is distant compared to Proxima Centauri.

35. A shooting star is actually:
    A. A falling star from the sky
    B. A meteor burning up in the atmosphere
    C. A spacecraft landing
    D. A comet’s nucleus
    Correct Answer: B — A meteor burning up in the atmosphere
    Explanations:
    A: Incorrect — there are no falling “stars”; the term is colloquial.
    B: Correct — small meteoroids heat up and glow as meteors (shooting stars).
    C: Incorrect — spacecraft re-entry looks different and isn’t termed shooting star.
    D: Incorrect — comet’s nucleus is the solid core, not the streak seen as a shooting star.

36. Planets that are made mostly of gases are called:
    A. Rocky planets
    B. Gas giants (or gaseous planets)
    C. Dwarf planets only
    D. Moons
    Correct Answer: B — Gas giants (or gaseous planets)
    Explanations:
    A: Incorrect — rocky (terrestrial) planets are like Earth, Mars.
    B: Correct — Jupiter, Saturn (and Uranus, Neptune as ice giants) are gas/ice giants.
    C: Incorrect — dwarf planets are small solid bodies, not gas giants.
    D: Incorrect — moons orbit planets; they are not a planet type.

37. Which planet is known for its extremely cold surface and reddish dust?
    A. Venus
    B. Mars
    C. Jupiter
    D. Mercury
    Correct Answer: B — Mars
    Explanations:
    A: Incorrect — Venus is extremely hot, not cold.
    B: Correct — Mars is cold with iron-rich reddish dust covering its surface.
    C: Incorrect — Jupiter is a gas giant, not the cold red planet.
    D: Incorrect — Mercury has extreme temperature variations and is not red.

38. Which is true about outer planets compared to inner planets?
    A. Inner planets are gas giants and larger
    B. Outer planets are generally larger and mostly gaseous
    C. Outer planets have solid rocky surfaces like Earth
    D. Inner planets have rings like Saturn always
    Correct Answer: B — Outer planets are generally larger and mostly gaseous
    Explanations:
    A: Incorrect — inner planets (Mercury, Venus, Earth, Mars) are smaller and rocky.
    B: Correct — outer planets (Jupiter, Saturn, Uranus, Neptune) are larger and gaseous/icy.
    C: Incorrect — outer gas giants lack solid rocky surfaces like Earth.
    D: Incorrect — not all inner planets have rings (none do).

39. The study of stars, planets and other objects in space is called:
    A. Biology
    B. Geology
    C. Astronomy
    D. Meteorology
    Correct Answer: C — Astronomy
    Explanations:
    A: Incorrect — biology studies living organisms.
    B: Incorrect — geology studies Earth’s physical structure.
    C: Correct — astronomy is the science of celestial objects.
    D: Incorrect — meteorology studies the atmosphere and weather.

40. Satellites that orbit Earth and collect information about weather are called:
    A. Communication satellites
    B. Weather satellites
    C. Navigation satellites
    D. Space telescopes
    Correct Answer: B — Weather satellites
    Explanations:
    A: Incorrect — communication satellites relay signals for TV/phone.
    B: Correct — weather satellites monitor clouds, storms and climate data.
    C: Incorrect — navigation satellites assist GPS and location services.
    D: Incorrect — space telescopes observe distant objects, not directly used for weather.

41. Which planet has the fastest orbit around the Sun (shortest year)?
    A. Earth
    B. Mars
    C. Mercury
    D. Jupiter
    Correct Answer: C — Mercury
    Explanations:
    A: Incorrect — Earth’s year is longer than Mercury’s.
    B: Incorrect — Mars orbits more slowly.
    C: Correct — Mercury, being closest to the Sun, completes orbit fastest (~88 Earth days).
    D: Incorrect — Jupiter’s orbit takes ~12 Earth years.

42. What is the force that keeps planets in orbit around the Sun?
    A. Magnetism only
    B. Friction from space
    C. Gravitational force
    D. Wind pressure
    Correct Answer: C — Gravitational force
    Explanations:
    A: Incorrect — magnetism is not the dominant force for planetary orbits.
    B: Incorrect — space is nearly vacuum; friction is negligible.
    C: Correct — gravity between the Sun and planets keeps them in orbit.
    D: Incorrect — wind (solar wind) does not provide orbital binding.

43. Which of the following is true about Jupiter?
    A. It is a small rocky planet
    B. It is the largest planet in the solar system and a gas giant
    C. It has no moons
    D. It is closest to the Sun
    Correct Answer: B — It is the largest planet in the solar system and a gas giant
    Explanations:
    A: Incorrect — Jupiter is large and gaseous, not rocky.
    B: Correct — Jupiter is the largest planet and composed mainly of hydrogen and helium.
    C: Incorrect — Jupiter has many moons (e.g., Ganymede, Io).
    D: Incorrect — Jupiter is far from the Sun compared to inner planets.

44. Which planet is known as the Morning Star or Evening Star?
    A. Mercury only
    B. Venus
    C. Jupiter
    D. Saturn
    Correct Answer: B — Venus
    Explanations:
    A: Incorrect — Mercury can be seen near horizon but Venus is more famously called Morning/Evening Star.
    B: Correct — Venus is very bright and visible just after sunset or before sunrise, earning that nickname.
    C: Incorrect — Jupiter is bright but not commonly called Morning/Evening Star.
    D: Incorrect — Saturn is dimmer and not typically named so.

45. Which is NOT a characteristic of stars?
    A. They emit light
    B. They are composed of hot gases
    C. They orbit planets
    D. They have different brightness and colours
    Correct Answer: C — They orbit planets
    Explanations:
    A: Incorrect — stars emit their own light.
    B: Incorrect — stars are made of hot gases (mostly hydrogen/helium).
    C: Correct — planets orbit stars, not vice versa.
    D: Incorrect — stars vary in brightness and colour depending on size and temperature.

46. What do we call a path followed by a planet around the Sun?
    A. Axis
    B. Rotation
    C. Orbit
    D. Eclipse
    Correct Answer: C — Orbit
    Explanations:
    A: Incorrect — axis is an imaginary line a planet spins around.
    B: Incorrect — rotation is spinning on its axis.
    C: Correct — orbit is the curved path of a planet around the Sun.
    D: Incorrect — eclipse is an event when one body blocks another.

47. Which of the following is a danger of satellites re-entering Earth’s atmosphere uncontrolled?
    A. They make Earth spin faster
    B. Fragments may fall to Earth and cause damage
    C. They clean the air
    D. They increase sunlight production
    Correct Answer: B — Fragments may fall to Earth and cause damage
    Explanations:
    A: Incorrect — satellite re-entry doesn’t change Earth’s spin noticeably.
    B: Correct — uncontrolled re-entry risks debris reaching the surface and causing harm.
    C: Incorrect — re-entering debris does not improve air quality.
    D: Incorrect — satellites do not produce sunlight.

48. The Sun’s energy reaches Earth mainly by:
    A. Conduction through vacuum
    B. Radiation (light and heat)
    C. Convection via air currents alone
    D. Sound waves
    Correct Answer: B — Radiation (light and heat)
    Explanations:
    A: Incorrect — conduction requires material; space is a vacuum.
    B: Correct — electromagnetic radiation (sunlight) carries energy through space.
    C: Incorrect — convection occurs within atmospheres but not across vacuum from Sun to Earth.
    D: Incorrect — sound cannot travel through vacuum and is not the Sun’s energy carrier.

49. Which feature helps us know Earth’s rotation axis direction?
    A. Position of the Sun only at noon
    B. Polaris (North Star) helps indicate north direction
    C. Moon phases alone
    D. Presence of clouds
    Correct Answer: B — Polaris (North Star) helps indicate north direction
    Explanations:
    A: Incorrect — Sun position varies by time and season, not a steady axis indicator.
    B: Correct — Polaris lies nearly above Earth’s North Pole, aiding orientation and indicating axis direction.
    C: Incorrect — Moon phases do not point out Earth’s axis direction.
    D: Incorrect — clouds are temporary and irrelevant for axis direction.

50. Which of the following is NOT true about astronauts working on the Moon?
    A. They wear space suits for protection
    B. They need oxygen supply
    C. They can walk normally as on Earth without aid
    D. They must manage communication with Earth
    Correct Answer: C — They can walk normally as on Earth without aid
    Explanations:
    A: Incorrect — suits are essential for temperature, pressure and oxygen.
    B: Incorrect — oxygen supply is vital.
    C: Correct — Moon’s gravity (~1/6th of Earth) and lack of atmosphere mean walking is different; movement is aided by suits and training.
    D: Incorrect — communication with Earth is maintained via radios and mission control.

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