Gate 1997 1.2

Gate 1997

1.2 The vernal equinox occurs on

(A) March 21   

(B) June 21   

(C) September 21

(D) December21

A) March 21

Equinox: The Sun is exactly above the Equator and day and night are of equal length, An equinox occurs twice a year, around 21 march and 23 September,

At equinox the sun is at one of the two opposites points on the celestial sphere where the celestial equator and ecliptic intersect. These point of intersection are called equinoctial points. Classically these vernal point and the autumnal point.

In the Northern Hemisphere, the vernal equinox falls about March 20 or 21, as the Sun crosses the celestial equator going north. In the Southern Hemisphere, the equinox occurs on September 22 or 23, when the Sun moves south across the celestial equator. According to the astronomical definition of the seasons, the vernal equinox also marks the beginning of spring, which lasts until the summer solstice (June 20 or 21 in the Northern Hemisphere, December 21 or 22 in the Southern Hemisphere).