Question

the length of day and night is not equal at all places on earth

Answer 1

the length of day and night is not equal at all the places of earth as Earth is in the shape of join which is similar to a sphere and when a light is thrown from a source on a sphere assuming that it is a Earth and then repeat it at a uniform speed with letting it revolve around the source some places will experience more time of light whereas some places will experience less time of flight which would lead to unequal time of days and night at all places places of the Earth