Question map
Which one of the following correctly explains the change in seasons on Earth?
Explanation
The change in seasons on Earth is primarily caused by the tilt of the Earth's axis of rotation relative to its orbital plane around the Sun [1][2]. This tilt, known as obliquity, is approximately 23.5 degrees. As the Earth revolves around the Sun, the axis remains fixed in space, causing different hemispheres to be tilted toward or away from the Sun at different times of the year [1]. When a hemisphere is tilted toward the Sun, it receives more direct solar radiation and experiences longer daylight hours, resulting in summer; conversely, the hemisphere tilted away experiences winter [1][3]. While the Earth's rotation on its axis causes day and night [2], and its revolution around the Sun determines the length of the year, it is the axial tilt that creates the seasonal cycle [1].
Sources
- [1] Science-Class VII . NCERT(Revised ed 2025) > Chapter 12: Earth, Moon, and the Sun > 12.2.2 Seasons on the Earth > p. 177
- [2] Science-Class VII . NCERT(Revised ed 2025) > Chapter 12: Earth, Moon, and the Sun > In a Nutshell > p. 184
- [3] Science-Class VII . NCERT(Revised ed 2025) > Chapter 12: Earth, Moon, and the Sun > 12.2.2 Seasons on the Earth > p. 178