universe & solar system section 9 MCQ Questions & Answers Detailed Explanation

Answer: (c)

Answer: (a)

Answer: (d)

As the furthest orbiting planet in the Solar System,

• Neptune has the longest year, taking 164.8 Earth years to complete a single orbit of the Sun.
• Saturn has the most moons i.e. 62.
• Earth has 71% water.
• Venus has the longest day of any planet in our solar system. It completes one rotation every 243 Earth days. Its day lasts longer than its orbit. It orbits the Sun every 224.65 Earth days, so a day is nearly 20 Earth days longer than its year.

Answer: (d)

Yes, the planets orbit in or close to a plane around the sun called the ecliptic.

The ecliptic is inclined 7 degrees from the planet of the Sun’s equator.

Answer: (a)

Venus 'overtakes' the Earth every 584 days as it orbits the Sun.

As it does so, it changes from the 'Evening Star', visible after sunset, to the 'Morning Star', visible before sunrise.

Answer: (b)

Pluto was discovered by Clyde Tombaugh in 1930. According to International Astronomical Union (IAU) on August 24, 2006, Pluto is considered a dwarf planet. According to the definition, there are currently eight planets and five dwarf planets known in the solar system.

The five dwarf planets are Pluto, Ceres, Eris, Make make and Haumea. Pluto has been given number 134340.