UPSC Prelims PYQ | Volcano
Q1. Pumice is derived from (a) Volcanic rock (b) Sedimentary rock (c) Igneous rock (d) Acid lava (UPSC Prelims 1986) Answer: (a) Volcanic rock Explanation: Pumice is a light, porous rock formed during volcanic eruptions when gas-rich lava cools rapidly. Its frothy texture is due to trapped gas bubbles, confirming its origin from volcanic rock.