All Free Everyday Science MCQs with Answers

71. Solar wind is caused by the high temperature and pressure in the sun's which atmosphere?

• A. Photosphere
• B. Chromosphere
• C. Corona
• D. A and B

Explanation: The corona is the Sun's extremely hot outer atmosphere, where the solar wind originates and is accelerated. The photosphere and chromosphere are lower atmospheric layers.

72. The solar wind is a stream of charged particles mostly?

• A. protons and electrons; flows out from the sun
• B. electrons; flows out from the sun
• C. protons; flows out from the sun
• D. protons and electrons; revolves around the sun

Explanation: Solar wind consists mainly of ionised hydrogen, meaning protons and electrons, streaming outward from the Sun. It is a flow away from the Sun, not a circulation around it.

73. Some objects from the Kuiper belt are classified as "plutoids" and include?

• A. Pluto, Cris, and Yeres
• B. Pluto, Bris, and Teres
• C. Pluto, Eris, and Ceres
• D. Yeres, Teres, Ceres

Explanation: Pluto, Eris and Ceres are named dwarf planets, but only Pluto and Eris are officially classified as plutoids because they orbit beyond Neptune; Ceres is included in this commonly used but technically loose grouping. The misspelled names in the other options are distractors.

74. The Oort cloud is estimated to be about __________ AU away from the sun?

• A. 100,000
• B. 200,000
• C. 300,000
• D. 400,000Purchasing Educational Biology Kits

Explanation: The Oort cloud is a distant, roughly spherical reservoir of icy bodies whose outer region is commonly estimated to reach about 100,000 AU from the Sun. It is much farther away than the Kuiper belt.

75. Which of the following is a region of the solar system even farther out than the Kuiper belt?

• A. The Gort cloud
• B. The Oort cloud
• C. The Fort cloud
• D. The Nort cloud

Explanation: The Oort cloud lies far beyond the Kuiper belt and is thought to surround the solar system as a distant spherical shell. The other three names are not recognised solar-system regions.

76. The Kuiper belt is a region of the solar system beyond?

• A. Venus
• B. Saturn
• C. Neptune
• D. Earth

Explanation: The Kuiper belt begins beyond Neptune, the outermost of the eight major planets. It contains many icy bodies, including Pluto.

77. Most asteroids orbit the sun in a region called the asteroid belt between?

• A. Mars and Jupiter
• B. Jupiter and Saturn
• C. Mercury and Neptune
• D. Venus and Uranus

Explanation: The main asteroid belt occupies the gap between Mars and Jupiter. Jupiter's strong gravity helped prevent this material from forming another planet.

78. Asteroids are made mostly of?

• A. Rock, metal, ice and dust
• B. Rock and metal
• C. Metal and gas
• D. Metal, gas and rock

Explanation: Most asteroids are rocky or metallic bodies, unlike comets, which contain much more ice and dust. Gas is not a major constituent of typical asteroids.

79. Comets are often called what?

• A. Dusty snowballs
• B. Filthy snowballs
• C. Dirty snowballs
• D. Impure snowballs

Explanation: Comets are popularly called dirty snowballs because they contain frozen volatile substances mixed with dust and rocky material. Their icy surfaces produce the coma and tail when heated by the Sun.

80. As comets get close to the sun, they start to "melt" and release gas and dust. This gas and dust forms what?

• A. "coma" around the comet's nucleus and a long tail that points away from the sun
• B. "coma" that points away from the sun and a long tail around the comet's nucleus
• C. Only "coma" around the comet's nucleus
• D. Only a long tail that points away from the sun

Explanation: Solar heating causes a comet's ices to sublimate, forming a coma around its nucleus and a tail directed generally away from the Sun by sunlight and the solar wind. The tail does not simply trail behind the comet's path.