Solved UPSC CDS/OTA Question
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Q · Rocks and Rock Cyclemedium · 45s
Which igneous rock forms when lava cools quickly on the Earth’s surface?
TopicRocks and Rock Cycle
Question Typemultiple choice
Difficultymedium
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
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Basalt is an extrusive igneous rock formed when lava cools rapidly on the Earth’s surface. The fast cooling does not allow large crystals to form, resulting in basalt’s fine-grained texture. This contrasts with intrusive igneous rocks, like granite, which cool slowly underground, producing coarse grains.
Final Answer: Option B - Basalt