Which one of the following is the longest Latitude?
- (a)90 degree Latitude
- (b)23.5 degree Latitude
- (c)0.0 degree Latitude
- (d)66.5 degree Latitude
Answer
Why
Correct — C, 0.0 degree Latitude. The 0° parallel is the Equator. Parallels of latitude are circles whose length shrinks steadily from the Equator towards the poles; the Equator is the largest of them (a great circle, about 40,075 km around), so 0° latitude is the longest latitude.
Why the others are wrong
- (a)90 degree Latitude — 90° latitude is the North or South Pole — not a circle at all but a single point, so it is the shortest, not the longest, 'latitude'.
- (b)23.5 degree Latitude — 23.5° is the Tropic of Cancer/Capricorn; being well away from the Equator, its circle is noticeably shorter than the Equator.
- (d)66.5 degree Latitude — 66.5° is the Arctic/Antarctic Circle, close to the poles, so its parallel is much shorter than the Equator.
Concept
Latitudes (parallels) are imaginary east–west circles measured in degrees north or south of the Equator (0°) up to the poles (90°). Because the Earth is a sphere, these circles get smaller as you move poleward: the Equator is the longest parallel and is a great circle, while the poles are just points.
The question rewards recalling that the Equator is 0° latitude and the longest parallel. The distractors are all famous latitudes (Tropics at 23.5°, Polar Circles at 66.5°, Poles at 90°) that are progressively shorter, so identifying 0° as the Equator settles it.
Key facts
- 0° latitude is the Equator — the longest parallel and a great circle (~40,075 km).
- 23.5° N/S are the Tropics of Cancer and Capricorn.
- 66.5° N/S are the Arctic and Antarctic Circles.
- 90° N/S are the North and South Poles — points, not circles.
Parallels shrink from the Equator to the poles, so 0° latitude is the longest.
Study next
Common traps
- Reading '90° latitude' as a large circle — it is actually a point (the pole).
- Confusing latitudes (parallels, unequal length) with longitudes (meridians, all equal in length).
Asked as 'which is the longest/shortest latitude', or by testing which lines are great circles.
Related PYQs
Consider the following lines of Longitude and Latitude: 1. Prime Meridian; 2. Tropic of Cancer; 3. Equator. Which of the above lines is/are a Great Circle?
- (a) 1, 2 and 3
- (b) 1 and 2 only
- (c) 1 and 3 only
- (d) 3 only
Answer(d) 3 only
Same concept — the Equator is the only parallel that is a great circle, i.e., the longest latitude, exactly the property tested in this question.
Practice
- practice — not a real PYQ
Which one of the following parallels of latitude is a great circle?
- (a)Tropic of Cancer
- (b)Arctic Circle
- (c)Equator
- (d)Tropic of Capricorn
Answer(c) Equator — the only parallel that is a great circle (all meridians are also great circles). - practice — not a real PYQ
The latitude 66.5° North is known as the
- (a)Tropic of Cancer
- (b)Arctic Circle
- (c)Equator
- (d)Antarctic Circle
Answer(b) Arctic Circle — 66.5° N; the Antarctic Circle is 66.5° S.