All Free Everyday Science MCQs with Answers

21. Halley's Comet is the only known short-period comet that is consistently visible to the naked eye from Earth, appearing every 72-80 years. It last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-_________?

• A. 2065
• B. 2061
• C. 2040
• D. None of These

Explanation: Halley's Comet takes about 75 years to orbit the Sun, so its return after 1986 is expected in 2061. Its long period distinguishes it from comets that return within a few years.

22. According to Big Bang Theory, the Universe began about __________ billion years ago.

• A. 10 - 20
• B. 20 - 30
• C. 30 - 40
• D. 40 - 50

Explanation: Modern measurements place the Big Bang at about 13.8 billion years ago, which falls within the 10–20 billion-year range. The wider ranges begin far above the accepted estimate.

23. The planets visible to us without using a telescope are __________?

• A. 3
• B. 4
• C. 5
• D. 6Physics

Explanation: Five planets can normally be seen with the unaided eye: Mercury, Venus, Mars, Jupiter and Saturn. Uranus is usually too faint for ordinary naked-eye observation.

24. The bodyguard of the Earth is __________ that save the Earth from many Comets and Asteroids.

• A. Mars
• B. Saturn
• C. Uranus
• D. Jupiter

Explanation: Jupiter’s enormous mass and strong gravity can attract or deflect some comets and asteroids, leading to its popular description as Earth’s bodyguard. This is an informal description, not complete protection from impacts.

25. 1 light year = ?

• A. 9.5×106 km
• B. 9.5×109 km
• C. 9.5×1012 km
• D. 9.5×1018 km

Explanation: A light-year is the distance light travels in one year, approximately 9.46 × 10¹² kilometres. It is a unit of distance, not time.

26. The Great Spot is on the planet __________?

• A. Saturn
• B. Venus
• C. Mars
• D. Jupiter

Explanation: The Great Red Spot is a gigantic, long-lasting storm in Jupiter’s atmosphere. Its reddish appearance and oval shape make it a distinctive feature of the planet.

27. The planet which is easily visible from the Earth is?

• A. Mercury
• B. Venus
• C. Mars
• D. Jupiter

Explanation: Venus is the easiest planet to see because its clouds reflect sunlight strongly, making it the brightest planet in Earth’s sky. It is commonly called the morning star or evening star.

28. In general, Comets have __________ orbits

• A. Elliptical
• B. Highly elliptical
• C. Circular
• D. Parabolic

Explanation: Most comets follow highly elliptical orbits, travelling far from the Sun and returning after a period. Some long-period comets may have nearly parabolic paths, but that is not the general answer.

29. The planet that moves round the Sun at the highest speed is_________?

• A. Jupiter
• B. Venus
• C. Mars
• D. Mercury

Explanation: Mercury moves fastest around the Sun because it is the closest planet and has the shortest orbital period, about 88 Earth days. Its average orbital speed is higher than that of the other listed planets.

30. The nearest planet to the Earth is _________?

• A. Venus
• B. Mercury
• C. Mars
• D. Moon

Explanation: Venus is traditionally identified as Earth's nearest planet because it can come closer to Earth than any other planet. Mercury is the closest planet to the Sun, which makes it a tempting but incorrect choice here.