Question

The precession period of Earth is:

• A. 24 hours
• B. 365.25 days
• C. 18.6 years
• D. 26,000 years

Hint:

Precession is a slow movement of Earth's rotational axis; remember its period is thousands of years, not hours or days.

Answer 1

The Correct Option is D

In the passage, precession is described as a very gradual movement of the Earth's axis, caused by the gravitational forces of the Sun and the Moon acting on the Earth's equatorial bulge.
It states that precession causes the Earth’s axis to slowly trace a circular path on the celestial sphere in a period of about 26,000 years.
Option (a) 24 hours refers to Earth’s daily rotation (diurnal spin), not precession.
Option (b) 365.25 days refers to Earth's revolution around the Sun, defining a year, not precession.
Option (c) 18.6 years refers to the nutation cycle, another wobble in Earth's axis, not precession.
Therefore, option (d) 26,000 years is correct as it matches the precession period mentioned in the passage.