Scale

Scale

Scale is the relationship between the distance on the map and distance on the Earth’s surface. A general definition of scale is that is is a ratio between the distance on a map and the corresponding distance on the Earth’s surface.

Scale = Map Distance/Ground Distance

 It is an important element of a map because it gives relative picture of ground reality. 

Scales can be expressed in three ways-

1. Statement Scale

2. Representative Fraction

3. Linear or Graphical Scale

1. Statement 

The scale may be indicated in the form of a written statement. The scale is written as 1cm to 1km. This means that 1cm on the map corresponds to 1km on the ground. This method of expressing is not very useful.

2. Representative Fraction

It is also called numerical scale. It is expressed as the ratio of map distance and ground distance. For example 1:50000 means 1 unit on the map corresponds to 50000 units on the ground. The advantage of of RF is that it can be used universally irrespective of  of the local unit of measurement of distance. The map can be reduced or enlarged without changing the RF.

3. Linear or Graphical scale

This scale is expressed as a horizontal or straight line. The bases are divided into a number of equal parts and are marked to show what these divisions represent on actual ground. The advantage of this scale is that it remains true even after reduction or enlargement of the map.

Types of Scale

1. Large Scale - Upto 1:50000.

2. Medium Scale Between 1:50000 to 1:1000000.

3. Small Scale - 1:1000000 and above.

Questions related to this topic.

1. In a 1:50000 scale map how much distance would be on the ground for 5cm in the map.

a) 250m     b) 25000m

c) 2500m.  d) 25m

2. When 2cm on the map = 200m on the ground then tick on the correct option of the scale.

a) 1:1000. b) 1:5000

c) 1:20000 d) 1:10000

3. On a 1:250000 scale map a place is located about 5000Km from your location on the ground then what is the distance on the map.

a) 20cm.  b) 200cm

c) 2cm.    d) 2000cm

4. On a statement scale when written as 1cm to 10Km. Then what it will be in the RF scale.

5. The true formula of scale is

a) Scale=Map Distance/Ground distance

b) Scale=Ground Distance/Map distance

c) All of the above

d) None of the above.