Free Environment and Atmosphere MCQs with Answers

91. Our atmosphere consists of___________ Oxygen approximately?

• A. 11% Oxygen approximately
• B. 21% Oxygen approximately
• C. 31% Oxygen approximately
• D. None of these

Explanation: Oxygen makes up approximately 21% of dry air by volume. Nitrogen is the larger component at about 78%.

92. Our atmosphere comprises of __________ Nitrogen?

• A. 38% Nitrogen
• B. 58% Nitrogen
• C. 78% Nitrogen
• D. None of these

Explanation: Nitrogen constitutes approximately 78% of Earth’s dry atmosphere. Most of the remaining air is oxygen, with small amounts of other gases.

93. Which of the following is a volcanic plateau?

• A. Antrum Plateau
• B. Brazilian Plateau
• C. Anatolia Plateau
• D. Tibetan Palteau

Explanation: The Antrim Plateau in Northern Ireland is a volcanic plateau formed mainly from extensive basalt lava flows. “Antrum” is a misspelling of Antrim, but it clearly identifies the intended option.

94. ________ is an instrument used in determining the directions of movement of clouds.

• A. Nephoscope
• B. Stethoscope
• C. Metroscope
• D. None of the above

Explanation: A nephoscope is used to observe and determine the direction and movement of clouds. A stethoscope is a medical instrument for listening to internal body sounds.

95. _________ means a line on a map connecting points having the same atmospheric pressure at a given time or on average over a given period.

• A. Isobar
• B. Isobath
• C. Isohel
• D. Isohyet

Explanation: An isobar joins points with equal atmospheric pressure. By contrast, an isobath shows equal water depth, an isohel equal sunshine, and an isohyet equal rainfall.

96. Ibex is a wild alpine ________ found in Himalaya?

• A. Dog
• B. Hen
• C. Sheep
• D. Goat

Explanation: An ibex is a wild mountain goat with large curved horns, adapted to rocky alpine regions such as the Himalayas. It is not a sheep, although both are hoofed ruminants.

97. Highest Clouds are ___________?

• A. Cirrocumulus
• B. Cirrus
• C. Cirrostratus
• D. All of these Science

Explanation: Cirrus, cirrocumulus and cirrostratus are all classified as high-level clouds, generally forming at great heights in the troposphere. Therefore, all the listed cloud types fit.

98. Marble and Slate are which type of rock?

• A. Igneous
• B. Sedimentary
• C. Metamorphic
• D. Non of These

Explanation: Marble forms when limestone is changed by heat and pressure, while slate forms mainly from shale under low-grade metamorphism. Both are therefore metamorphic rocks.

99. Coldest point in atmosphere is?

• A. Tropopause
• B. Mesopause
• C. Exopause
• D. None of these

Explanation: The mesopause is generally the coldest atmospheric boundary, with temperatures that can fall near minus 90°C. Above it, temperatures rise again in the thermosphere.

100. The material that comes out of a volcano at the time of eruption is:

• A. Solid, liquid, gaseous
• B. Solid and liquid
• C. Solid and gaseous
• D. None of these

Explanation: A volcanic eruption can release solid ash and rock fragments, liquid lava, and gases such as steam and carbon dioxide. Hence all three physical states are represented.