2015 · Q18
Statement ISideral day is shorter than Solar day.
Statement IIThe motion of the Earth in its orbit around the Sun is termed as revolution.
General KnowledgeGeography
- ABoth the statements are individually true and Statement II is the correct explanation of Statement I.
- BBoth the statements are individually true, but Statement II is not the correct explanation of Statement I.
- CStatement I is true, but Statement II is false.
- DStatement I is false, but Statement II is true.
Explanation
A sidereal day (about 23 h 56 m) is Earth's rotation period measured against distant stars, while a solar day (24 h) is measured against the Sun. Because Earth also advances about 1° along its orbit each day — its revolution — it must rotate roughly 361° to bring the Sun back to the same meridian; that extra rotation takes about four minutes, making the solar day longer. Both statements are individually true, and Statement II (revolution, i.e. orbital motion) is precisely the correct explanation of Statement I. The answer is A.