Universe - Practice Test 4

Attempt the quiz above first, then review every question with its correct answer and a short explanation below.

1. Q1.The mean distance between the Earth and the Sun is called:

   • A.Light Year
   • B.Astronomical Unit (AU)✓ Correct Answer
   • C.Parsec
   • D.Kilometer

   Explanation: 1 Astronomical Unit (AU) is the average distance between Earth and Sun (~150 million km).

2. Q2.Which planet revolves around the Sun in the shortest time?

   • A.Mercury✓ Correct Answer
   • B.Earth
   • C.Jupiter
   • D.Neptune

   Explanation: Mercury orbits the Sun in about 88 Earth days.

3. Q3.The belt of 'Zodiac' consists of how many constellations?

   • A.10
   • B.12✓ Correct Answer
   • C.13
   • D.88

   Explanation: The Zodiac is divided into 12 signs/constellations (Aries to Pisces).

4. Q4.Which planet has a density less than water (it would float)?

   • A.Earth
   • B.Mars
   • C.Saturn✓ Correct Answer
   • D.Mercury

   Explanation: Saturn has the lowest density (0.687 g/cm³), which is less than water (1 g/cm³).

5. Q5.The first artificial satellite launched into space was:

   • A.Apollo 11
   • B.Sputnik 1✓ Correct Answer
   • C.Explorer 1
   • D.Aryabhata

   Explanation: Sputnik 1 was launched by the Soviet Union on October 4, 1957.

6. Q6.Which planet is known as the 'Lord of the Heavens'?

   • A.Mars
   • B.Jupiter✓ Correct Answer
   • C.Saturn
   • D.Uranus

   Explanation: Jupiter is named after the king of the Roman gods, the Lord of the Heavens.

7. Q7.The shape of the Earth is best described as:

   • A.Perfect Sphere
   • B.Flat
   • C.Geoid✓ Correct Answer
   • D.Circular

   Explanation: The Earth is an oblate spheroid, and its shape is specifically called a 'Geoid' (Earth-like).

8. Q8.Day and Night are caused by:

   • A.Revolution of Earth
   • B.Rotation of Earth✓ Correct Answer
   • C.Tilt of Earth's axis
   • D.Revolution of Moon

   Explanation: The rotation of the Earth on its axis causes day and night.

9. Q9.Seasons are caused by:

   • A.Rotation of Earth
   • B.Revolution of Earth and Axial Tilt✓ Correct Answer
   • C.Distance from Sun
   • D.Ocean currents

   Explanation: Seasons are caused by the tilt of Earth's axis and its revolution around the Sun.

10. Q10.The Earth is closest to the Sun on:

    • A.January 3 (Perihelion)✓ Correct Answer
    • B.July 4 (Aphelion)
    • C.March 21
    • D.September 23

    Explanation: Earth is at Perihelion (closest) around January 3rd.

11. Q11.The Earth is farthest from the Sun on:

    • A.January 3
    • B.July 4 (Aphelion)✓ Correct Answer
    • C.June 21
    • D.December 22

    Explanation: Earth is at Aphelion (farthest) around July 4th.

12. Q12.Equinox means:

    • A.Longest day
    • B.Shortest night
    • C.Equal day and night✓ Correct Answer
    • D.No sun

    Explanation: Equinox implies equal duration of day and night all over the earth (March 21 & Sept 23).

13. Q13.The International Space Station (ISS) is located in:

    • A.Geostationary Orbit
    • B.Low Earth Orbit (LEO)✓ Correct Answer
    • C.Polar Orbit
    • D.Lunar Orbit

    Explanation: The ISS orbits Earth in Low Earth Orbit at an altitude of about 400 km.

14. Q14.Which planet is called the 'Lying Planet' because it rotates on its side?

    • A.Uranus✓ Correct Answer
    • B.Neptune
    • C.Saturn
    • D.Mars

    Explanation: Uranus has an axial tilt of 98 degrees, making it appear to roll on its side.

15. Q15.Who discovered the planet Uranus?

    • A.Galileo
    • B.William Herschel✓ Correct Answer
    • C.Newton
    • D.Copernicus

    Explanation: William Herschel discovered Uranus in 1781.

16. Q16.Which celestial body is considered a 'Fossil Planet'?

    • A.Moon✓ Correct Answer
    • B.Mars
    • C.Asteroids
    • D.Comets

    Explanation: The Moon is sometimes called a fossil planet because it has remained geologically dormant for billions of years.

17. Q17.The pole star indicates which direction?

    • A.South
    • B.North✓ Correct Answer
    • C.East
    • D.West

    Explanation: The Pole Star (Polaris) lies almost directly above the North Pole, indicating North.

18. Q18.A group of stars is known as:

    • A.Solar System
    • B.Galaxy✓ Correct Answer
    • C.Universe
    • D.Comet

    Explanation: A Galaxy is a massive system of stars, gas, and dust bound by gravity.

19. Q19.Which planet is the brightest in the solar system?

    • A.Jupiter
    • B.Mercury
    • C.Venus✓ Correct Answer
    • D.Mars

    Explanation: Venus reflects about 70% of sunlight due to its clouds, making it the brightest.

20. Q20.The visible part of the Sun is called:

    • A.Corona
    • B.Photosphere✓ Correct Answer
    • C.Chromosphere
    • D.Core

    Explanation: The Photosphere is the luminous visible surface of the Sun.