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.
