Question 1

Question 1Define Contour.

Accepted Answer

Contours are lines drawn in brown colour, joining places having the same elevation above mean sea level. The contour lines on a map provide a useful insight into the topography of an area.

Question 2

Question 2What is hachuring used for?

Accepted Answer

Hachures are short lines representing directions of a slope. For steep slopes they are drawn closer together than for the gentle slopes. They cannot be used for flat ground.

Question 3

Question 3What is a gradient? How is it determined?

Accepted Answer

The term gradient refers to the slope of the concerned feature. It is determined by calculating the Horizontal Equivalent. Horizontal Equivalent is the distance between the two contour lines. If it is less, the slope is steep and if it is more, the slope is gentle.

Question 4

Question 4What are form lines?

Accepted Answer

Form lines are the contour lines drawn as broken lines which are used to indicate the approximate heights above sea level. They are used to indicate the elevations of the area which are not accessible for proper survey.

Question 5

Question 5What are spot heights? How are they represented on the map?

Accepted Answer

Spot heights are points which show the height of that point from the mean sea level. They are represented by a dot with a number beside it. If the spot height is shown as .220, it means that the height of that point is 220 m from the mean sea level.

Question 6

Question 6What is meant by Bench marks? How are they represented on the map?

Accepted Answer

Bench marks are the permanent survey points shown by a stone or a building. They show the height of that point above sea level through accurate survey. The Bench mark is represented on the map as 'BM' with a number beside it. For example, 'BM 230 m' shows a bench mark with 230 m height.

Question 7

Question 7What is meant by index contours? In what way are they useful?

Accepted Answer

In a contour map, every fifth line in multiple of 20 m is accentuated and is called the Index Contour.Index contours make the contour map distinct. They also indicate whether the height of the terrain is increasing or decreasing.

Question 8

Question 8Differentiate between vertical interval and horizontal equivalent.

Accepted Answer

Sl.No.Vertical intervalHorizontal equivalent1.It is the vertical distance between two contours.It is the horizontal distance between two contour.2.It is generally 20 m.It varies according to the slope of land.

Question 9

Question 9What is a grid?

Accepted Answer

The network of horizontal and vertical lines, or the Eastings and Northings on a topo sheet is called the grid.

Question 10

Question 10What points should be kept in mind while reading a grid reference?

Accepted Answer

The Following point should be kept in mind while reading a grid reference:Origin is the south-west corner of the map. The reading on the map is always taken with reference to this origin.Eastings are always read to the East of the origin.Northings are always read to the North of the origin.While giving a grid reference, Eastings are always stated first, followed by the Northings.The readings are always taken to the right of the Eastings and to the North of the Northings

Question 11

Question 11(d)Identify and name the relief features represented in the given diagram.

Accepted Answer

A hill with gentle and steep slope

Question 12

Question 11(e)Identify and name the relief features represented in the given diagram.

Accepted Answer

A conical hill with steep slope

Question 13

Question 11State any two means of communication in grid square 4485A dry river and pack tractA railway track and metalled roadCart tract and footpathExpress way and cart track

Accepted Answer

A railway track and metalled road

Question 14

Question 12What is meant by BM 224 in grid square 4485?It is Bench Mark, cut on a rock wall or a building showing the height of that mark above sea level is 224 mIt is Benchmark, 224 m above sea levelThe height of the point where it is writtenIt is the height of the sand dune above sea level

Accepted Answer

It is Bench Mark, cut on a rock wall or a building showing the height of that mark above sea level is 224 m

Question 15

Question 13Which drainage pattern is seen in grid square 3893?RadialDendriticTrellisedIntermittent

Accepted Answer

Trellised

Question 16

Question 16The blue line in the main river indicatesA perennialA thin perennial NalaA thin water channelA stream

Accepted Answer

A thin water channel

Question 17

Question 17What does the number 381 indicate in grid square 4388?Approximate height is 381Relative heightSpot height showing the height of a particular point above sea level is 381 mSpot height showing the height of that place is 381

Accepted Answer

Spot height showing the height of a particular point above sea level is 381 m

Question 18

Question 18What does △ 224 in grid square 2706 indicates?The height of a particular pointTriangulated height - showing the height of a point surveyed by the triangulated method is 224mTriangulation survey showing the height of a point of 224mApproximate height of the point is 224 m

Accepted Answer

Triangulated height - showing the height of a point surveyed by the triangulated method is 224m

Question 19

Question 19State the area of the grid square 5121, the scale being 2cm = 1km.4 sq km2 sq km1 sq km1 km

Accepted Answer

1 sq km

Question 20

Question 20Name the three types of communication shown in the grid square 6621.Metalled road, cart track, pack tractCart track, footpath, roadFootpath, pack track and metalled roadCart track, road and footpath

Accepted Answer

Footpath, pack track and metalled road

Interpretation of Topographical Maps — II

Answer the following questions

Multiple Choice Question