Question map
Consider the following statements. I. The tropical year is shorter than the sidereal year II. The solar day is longer than the sidereal day Which of the statements given above is/are correct?
Explanation
Statement I is correct as the tropical year (approximately 365.2422 days) is about 20 minutes shorter than the sidereal year (approximately 365.2564 days) [c1, t1, t7]. This difference arises due to the axial precession of the Earth, which causes the vernal equinox to 'move to meet' the Sun slightly before the Earth completes a full 360-degree orbit relative to fixed stars [t1, t8]. Statement II is also correct. A sidereal day is the time taken for one full 360-degree rotation relative to distant stars (approx. 23 hours 56 minutes), whereas a solar day is the time taken for the Sun to return to the same meridian [t3, t7]. Because the Earth moves along its orbit while rotating, it must rotate slightly more than 360 degrees to realign with the Sun, making the solar day about 4 minutes longer than the sidereal day [t2, t3].
Sources
- [1] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 11: Keeping Time with the Skies > A step further > p. 180
- [2] https://gml.noaa.gov/ozwv/dobson/papers/report6/appi.html