Given below are two statements: one is labeled as Assertion A and the other is labeled as Reason R.

Assertion (A): During an equinox the length of daylight is 12 hours everywhere on Earth.
Reason (R): On equinox the circle of illumination passes directly through the poles dividing the latitudes in half.

In the light of the above statements, choose the most appropriate answer from the options given below:

Correct option is A

Reason (R) is also correct: On an equinox, the circle of illumination passes directly through the poles, dividing the Earth into two equal halves, which is why all parts of Earth experience equal day and night lengths.

Since both statements are correct and Reason (R) directly explains Assertion (A), the correct answer is (a).

1. The equinox occurs twice a year, around March 21st and September 23rd, when the Earth’s axis is not tilted towards or away from the Sun.
2. Circle of illumination refers to the boundary between the day side and the night side of Earth. During an equinox, this circle runs through both poles, resulting in equal lengths of day and night.
3. Daylight duration on the equinox is 12 hours everywhere on Earth, except near the poles where it may slightly differ due to atmospheric refraction.
4. Equator experiences the most direct sunlight on the equinox, and the day length is exactly 12 hours.
5. The circle of illumination helps to explain why the day and night are divided equally across the globe during the equinox.