Question

why are days and nights are equal on 21 march at all places on the earth explain shortly answer​

Answer 1

Answer:

Days and nights are equal at all places on earth on March 21 because on this day sun rays will fall in the vertical direction towards the equator or at the center position of the earth. This supplies the equal light distribution from pole to pole which makes the day and night duration same.

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Answer 2

Answer:

why are days and nights are equal on 21 march at all places on the earth explain shortly answer

Explanation:

On 21st March and September 23rd, direct rays of the sun fall on the equator. At this position, neither of the poles is tilted towards the sun; so, the whole earth experiences equal days and equal nights. This is called an equinox.