Question

why there is equal duration of day and night at the equator please give a very easy answer in simple language

Answer 1

Heya friend!!

Actually there is not an equal duration of day and night at the equator. As the day is always longer than the night in summer and vice versa during winters, it is because the earths axis a little tilted at 23 and a half degree and the Earth rotates in its own axis.

The Equator lies exactly half way between the two tropics i.e. the tropic of cancer and the tropic of Capricorn. 

 Simple and shortest reason in terms of calculation and measurement can be- Because the circle of illumination(separates day from night) bisects the equator every day of the year.

Hope it really helps U!!