SSC Selection Post 2025 PYQ — Question 19

Correct Answer:-

The tilt of the Earth's axis

Explanation:-

Changes in seasons on Earth are primarily caused by the tilt of the Earth's axis as it orbits the sun. The Earth is tilted at an angle of approximately 23.5 degrees relative to its orbital plane. Because of this tilt, different hemispheres (Northern and Southern) receive varying amounts of direct sunlight throughout the year as the Earth orbits the Sun, leading to changes in temperature and seasonal transitions.

Key Points

Revolution: The combination of Earth's orbit around the Sun and its fixed axial tilt is the fundamental reason for the changing seasons.

Solstice and Equinox:

Solstice: Occurs when the Sun is at its maximum tilt relative to one of the hemispheres, resulting in the longest or shortest day of the year.

Equinox: Occurs when the Sun is positioned directly above the equator, resulting in nearly equal day and night lengths globally.

Debunking a Myth: Many people incorrectly assume that seasons change because of the Earth's distance from the Sun. However, Earth's orbit is nearly circular, and the distance variation is not the primary driver of seasons.

Important Questions and Answers

Question: At what angle is the Earth tilted on its axis?

Answer: The Earth is tilted at an angle of approximately 23.5 degrees.

Question: What would happen if the Earth's axis were not tilted?

Answer: If the Earth were not tilted, seasons as we know them would not exist, and the climate would remain relatively uniform throughout the year.