Explain with the help of a diagram, the part played by the inclination of Earth's axis in causing day and night of varying duration, except at the Equator.

The effect of the inclined axis on the duration of day and night is that their duration differs as shown in the diagram below:

1. At the Equator, place C would be at position C' after 12 hours.
   Distance CO = Distance OC'
   ∴ Length of day = Length of night.
2. On the Tropic of Cancer place B will be at B' after 12 hours.
   But distance BX is greater than B'X.
   ∴ Days are longer than nights.
3. On the Arctic Circle place A will be at position A' after 12 hours. AA' remains in continuous light in summer for six months.
   ∴ Day of 24 hours near the North Pole in summer.
4. Place D on the Tropic of Capricorn in the Southern Hemisphere will be at position D' after 12 hours.
   Distance DY (in light) is less than the distance D'Y (in darkness)
   ∴ Days are shorter than nights.
5. Place E on the Antarctic Circle remains in continuous darkness in winter.
   ∴ Night for 24 hours near the South Pole in winter for six months.