Prelims 2013 · Geography · Question 64
Variations in the length of daytime and nighttime from season to season are due to
Answer
revolution of the earth on a tilted axis
- (a) Earth's rotation on its axis: Rotation causes day and night to occur, but not the seasonal variation in their lengths. Incorrect.
- (b) Earth's revolution round the sun in an elliptical manner: The elliptical orbit mainly affects distance from the Sun slightly, not the changing duration of day and night. Incorrect.
- (c) Latitudinal position of the place: Latitude affects how much variation is experienced, but it is not the fundamental cause of seasonal change in day length. Not the correct cause here.
- (d) Revolution of the Earth on a tilted axis: The Earth's axial tilt (23.5°) combined with revolution around the Sun causes seasonal changes in the length of daytime and nighttime. Correct.