Q. On 21st June, the Sun (UPSC Prelims 2019)
Answer: does not set below the horizon at the Arctic Circle
Notes: The correct answer is [A] does not set below the horizon at the Arctic Circle. On June 21st, the Northern Hemisphere experiences the Summer Solstice, a point where the Earth's North Pole is tilted at its maximum toward the Sun.

• Arctic Circle (Statement A – Correct): During the Summer Solstice, the tilt of the Earth causes the entire region north of the Arctic Circle (66.5° N) to remain facing the Sun for a full 24-hour rotation. This phenomenon is known as the "Midnight Sun," where the Sun remains visible even at local midnight.
• Antarctic Circle (Statement B – Incorrect): On this day, the Southern Hemisphere is tilted away from the Sun. The region south of the Antarctic Circle (66.5° S) experiences 24 hours of darkness (Polar Night).
• Equator (Statement C – Incorrect): The Sun shines vertically overhead at the Equator during the Equinoxes (March 21st and September 23rd). On June 21st, the noon Sun is at an angle of approximately 66.5° at the Equator.
• Tropic of Capricorn (Statement D – Incorrect): The Sun shines vertically overhead at the Tropic of Capricorn (23.5° S) on December 21st or 22nd, which marks the Winter Solstice in the Northern Hemisphere.

On June 21st, the Sun's rays fall vertically on the Tropic of Cancer (23.5° N). This results in the longest day and shortest night of the year for locations in the Northern Hemisphere.