An imaginary line drawn on a globe to divide it into two equal parts is known…

Concept: Lines of latitude are imaginary circles drawn around the globe parallel to the Equator, each labelled by its angular distance north or south of the Equator (0°). A latitude circle splits the Earth into two truly equal halves only when its plane passes through the exact centre of the planet — geometrically this is possible at only one latitude value.

Application: The Equator is the 0° latitude line, lying exactly midway between the North Pole and the South Pole. Because its plane passes through the centre of the Earth, it divides the planet into the Northern Hemisphere and the Southern Hemisphere of equal size, which is exactly the division the question describes.

Why the other lines do not qualify:

• Tropic of Cancer (about 23.5° N) lies well north of the Equator, so it cuts off a much smaller northern portion of the globe than the portion remaining to its south.

• Tropic of Capricorn (about 23.5° S) lies well south of the Equator and, for the same geometric reason, also splits the globe unevenly.

• Arctic Circle (about 66.5° N) lies even closer to the North Pole, marking off only a small polar region rather than bisecting the sphere.

Cross-check: Any latitude circle other than 0° has the nearer pole’s cap on one side and a larger remaining area on the other; only the 0° circle (the Equator) is equidistant from both poles, confirming it is the unique line that produces two equal halves.