Question

How many types of contour lines are found on a Topographical map?
A. Three
B. Two
C. Seven
D. None of the above

Answer 1

Hint: Topographical maps are maps that show the shape and features of the surface of the earth of any particular area. They are maps of relatively smaller areas but with very detailed and extensive information about it. These maps use contour lines to show places with the same elevation.
Due to the extensive use of contour lines, topographical maps are also known as contour maps.

Complete answer:
As mentioned earlier, contour lines are used in topographical maps to connect all the places with the same elevation. Sometimes it is also used to show places with the same temperature or pressure. But the way the lines are drawn are the same. Whether the contours represent altitude or some other parameters is clearly stated in the key. The different kinds of contour lines are instead used to show different aspects of the same parameter (most commonly the altitude).

A. Contour lines are of three different kinds. They are the Index lines, Intermediate lines and the Supplementary lines. Thus, this is the correct option.

B. Only two types of lines wouldn't be enough to properly provide all the information in the map. It is not the correct option.

C. Seven different types of lines would again be too confusing and make the map way more complicated than needed. This too is an incorrect option.

D. Since three types is the correct answer, this is an incorrect option.

Therefore, the correct answer is Option A.

Note:
i) Index lines show the elevation of a place above sea level. They are the thickest contour lines and are usually labelled with numbers.
ii) Intermediate lines are thinner lines between the index lines. Usually, there are five intermediate lines after each index line.
iii) Supplementary lines are drawn as dotted lines. They are used to show flatter surfaces.