The correct option is (a).
Explanation
The Summer Solstice, typically occurring on June 21st, marks the position in Earth's revolution where the North Pole is tilted most directly towards the Sun. This orientation significantly influences the distribution of solar radiation (insolation) and the length of day and night across the hemispheres.
Statement-wise Analysis
- Statement 1 is Correct: During the Summer Solstice, the Sun's rays fall vertically overhead at the Tropic of Cancer ($23.5^\circ$ N). This results in the Northern Hemisphere receiving the maximum intensity of direct sunlight.
- Statement 2 is Incorrect: The longest day and shortest night occur in the Northern Hemisphere during this time. Conversely, the Southern Hemisphere is tilted away from the Sun, resulting in the shortest day and longest night.
- Statement 3 is Incorrect: Due to the direct insolation and longer daylight hours, the Northern Hemisphere experiences the summer season. The Southern Hemisphere, receiving oblique rays and shorter daylight, experiences the winter season.
Key Takeaway:
The Summer Solstice (June 21) is defined by the Sun being directly overhead at the Tropic of Cancer, causing summer conditions and the longest day in the Northern Hemisphere, while the Southern Hemisphere experiences winter.