(a) the earth’s rotation on its axis
(b) the earth’s revolution around the sun in an elliptical manner
(c) latitudinal position of the place
(d) revolution of the earth on a tilted axis
Answer: (d)
Option (d) is correct:
The variations in the length of daytime and night-time from season to season are due to the revolution of the earth on a tilted axis.
O Earth has two types of motion, namely rotation and revolution. Rotation is the movement of the earth on its axis. The movement of the earth around the sun in a fixed path or orbit is called Revolution.
O The axis of the Earth, which is an imaginary line, makes an angle of 66° with its orbital plane. The plane formed by the orbit is known as the orbital plane. The earth receives light from the sun. Due to the spherical shape of the earth, only half of it gets light from the sun at a time.
O The portion, facing the sun, experiences day while the other half away from the sun experiences night. The circle that divides the day from night on the globe is called the circle of illumination. The earth takes about 24 hours to complete one rotation around its axis. The period of rotation is known as Earth Day. Throughout its orbit, the earth is inclined in the same direction.
