
On 21st June, the Sun
- does not set below the horizon at the Arctic Circle
- does not set below the horizon at Antarctic Circle
- shines vertically overhead at noon on the Equator
- shines vertically overhead at the Tropic of Capricorn
Explanation
Option (a) is correct
- On 21st June, the northern hemisphere is tilted towards the sun. The rays of the sun fall directly on the Tropic of Cancer. As a result, these areas receive more heat. The areas near the poles receive less heat because the sun’s rays are slanted. The north pole is inclined towards the sun, and the places beyond the Arctic Circle experience continuous daylight for about six months. Since a large portion of the Northern Hemisphere is receiving sunlight, it is summer in the regions north of the equator. The longest day and the shortest night at these places occur on 21st June. At this time in the southern hemisphere, all these conditions are reversed. It is winter season there. The nights are longer than the days. This position of the Earth is called the summer solstice.
- On 22nd December, the Tropic of Capricorn receives direct rays of the sun as the south pole tilts towards it. As the sun’s rays fall vertically at the Tropic of Capricorn (23½° s), a larger portion of the southern hemisphere gets light. Therefore, it is summer in the southern hemisphere with longer days and shorter nights. The reverse happens in the northern hemisphere. This position of the earth is called the winter solstice.


