Question

Which of the following statements about the Great Circle are Correct?
A) The Great Circle is an imaginary circle which divides the earth into two equal hemispheres.
B) The Equator is the only great circle that can be drawn on the earth surface
C) An arc of a great circle on the surface of earth marks the shortest distance between two points on earth

Answer 1

Hint: Great circles are also known as orthodromes; they are the largest circle that can be drawn on any given sphere. If you have to cut it exactly in half you have to cut the sphere at one of its great circles.

Complete answer:
Now let us analyze the given options:
Option (A) A great circle is the one that circumnavigates the earth and passes through its centre. The Equator is just like one of the earth’s great circles which divides the earth into two equal halves which are called the northern and the southern hemispheres. Hence this option is correct
Option (B): The Equator is the great circle lying on the east-west line but there would be other great circles when we consider north-south longitude lines. This is because all the longitudes will also divide the earth into two equal hemispheres. Hence this option is incorrect
Option (C): The shortest distance between any two points on a circle is along the arc of that particular circle. This is a mathematical law that is applicable across the universe. Hence, it also means that the shortest distance between two points on the surface of the earth would definitely be via the arc of the Great Circle. Therefore, this option is also correct.

Thus, the correct answers are Option (A) and Option (C).

Note: The geometry of spheres is widely used for understanding the mapping of earth and other planets. All the longitudes on the earth are great circles. Longitudes including those north-south lines which we use to help describe where we are on earth.