The correct option is (c).
Explanation
Meridians of longitude are imaginary vertical lines on the Earth's surface that connect the North Pole to the South Pole. They are essential for determining time zones and the east-west position of a location relative to the Prime Meridian.
Statement-wise Analysis
- Statement 1 is Correct: Meridians are semi-circles that run vertically from the North Pole to the South Pole. Unlike latitudes, they do not form full circles individually; a meridian and its opposite anti-meridian together form a complete Great Circle.
- Statement 2 is Incorrect: The distance between two meridians is not constant. It is maximum at the Equator (approximately 111.3 km) and decreases progressively as one moves towards the poles, eventually becoming zero at the poles where all meridians converge.
- Statement 3 is Correct: All meridians of longitude are of equal length because they all extend from pole to pole. This is in contrast to parallels of latitude, which are full circles that decrease in circumference as they move from the Equator towards the poles.
Key Takeaway: Meridians of longitude are semi-circles of equal length that converge at the poles, whereas parallels of latitude are parallel circles of varying lengths that never intersect.