GeographyCBSE Class 11 · Map Projections

Map Projection: Need, Elements and Classification (Class 11 Practical Work in Geography, Chapter 4)

Updated 17 October 2026 · Fact-checked

A map projection is the method of transferring the graticule (the network of parallels and meridians) from the globe to a plane surface. Because the globe is not a developable surface, every flat map distorts shape, size, distance or direction, so projections are classified by drawing technique, developable surface, global property and source of light, and one property is chosen to preserve.

Each flat surface touches the globe at the equator, a parallel or a point, and distortion increases with distance from that contact.

Illustration drawn for QuestionBuddy.

Understand Map Projections: Need, Distortion, Elements of a Projection and Classification

Why this topic matters. This chapter carries 5 marks in the 30-mark practical exam; the definition, the reason for distortion and the classification are asked in the written test and viva. CBSE limits constructions to the conical projection with one standard parallel and Mercator's projection (covered on the next topic page).

1. Definition. The network of parallels and meridians is the graticule. Map projection is the method of transferring the graticule from the globe to a plane surface. It is also defined as the study of methods tried for transferring the graticule to a flat sheet, each preserving some properties.

2. Need. A globe is the best model of the earth: shapes, sizes, directions and distances are accurate. But it is expensive, hard to carry, cannot show minor details, and comparing regions on it is difficult. On the globe meridians are semicircles and parallels are circles; on a plane they become straight or curved intersecting lines.

3. Distortion. A flat paper stuck on a globe will not fit over a large area without distortion. If light is thrown from the centre of the globe, the image is distorted away from the point or line of contact, and distortion increases with distance. The globe is a non-developable surface, so shape, size and direction cannot all be kept at once.

4. Elements. (i) Reduced earth, a model at a reduced scale (radius = earth's radius divided by the scale denominator); (ii) parallels of latitude, circles parallel to the equator, unequal in length, 0 to 90 degrees N and S; (iii) meridians of longitude, semicircles from pole to pole, with Greenwich (0 degrees) as the reference; (iv) global properties: distance, shape, area and direction.

5. Classification. By drawing technique: perspective, non-perspective, conventional or mathematical. By developable surface: cylindrical, conical, zenithal; by point of contact: normal (equatorial), oblique, polar. By global property: equal area (homolographic), orthomorphic (true shape), azimuthal (true bearing), equidistant (true scale along selected lines). By source of light: gnomonic (light at the centre), stereographic (at the periphery opposite the point of contact), orthographic (at infinity).

6. Choice. No projection preserves all four properties, so one is chosen for the property the map's purpose needs.

Map Projections: Need, Distortion, Elements of a Projection and Classification: key facts

Definition: Graticule: network of parallels and meridians | Projection: transferring it to a plane surface; Globe is non-developable.
Elements: Reduced earth
Parallels of latitude
Meridians of longitude
Global properties: distance, shape, area, direction; Four elements.
Classification: Technique perspective, non-perspective, mathematical
Surface cylindrical, conical, zenithal
Property equal area, orthomorphic, azimuthal, equidistant
Light gnomonic, stereographic, orthographic; Four bases.
Contact: $N or ma l (e q u a t or ia l) ∣ O b l i q u e ∣ P o l a r$; Position of the developable surface.

Technique	perspective, non-perspective, mathematical
Surface	cylindrical, conical, zenithal
Property	equal area, orthomorphic, azimuthal, equidistant
Light	gnomonic, stereographic, orthographic

How to answer Map Projections: Need, Distortion, Elements of a Projection and Classification questions

Classification answers are best written as a table with the basis and the types.

1Name the basis (technique, surface, property, source of light).
2List the types under each with a clause of explanation.
3Add the example projection if known (conical, Mercator).
4Conclude that no projection keeps all properties.

Map Projections: Need, Distortion, Elements of a Projection and Classification in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Peeling an orange

Suppose a child peels an orange in one piece and tries to press the peel flat on a table.

What does this show about map projection?

Try it first, then show the solutionSolution

The curved surface does not flatten without tearing or stretching.
A globe is a non-developable surface so a flat map distorts.

Answer: It shows why every flat map has distortion.

Memory hook: Peel will not lie flat.

Choosing for a pilot

Suppose a navigator wants a chart in which a straight line gives a constant compass bearing.

Which global property must be preserved?

Try it first, then show the solutionSolution

Direction (bearing).
A projection preserving direction is chosen.

Answer: Direction (true bearing).

Memory hook: Need decides the projection.

Tricks to remember Map Projections: Need, Distortion, Elements of a Projection and Classification

Short memory aids. Say each one aloud once, then use it on a question the same day.

G-S-D-P
Graticule, Surface, Distortion, Property
Use it when: Core terms.
CCZ
Cylindrical, Conical, Zenithal
Use it when: Developable surfaces.
E-O-A-E
Equal area, Orthomorphic, Azimuthal, Equidistant
Use it when: Global properties.

Map Projections: Need, Distortion, Elements of a Projection and Classification: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Graticule · 1 mark · MCQBoard level

The network of parallels and meridians on a globe or map is called a:
(A) scale
(B) graticule
(C) legend
(D) contour

Try it first, then show the solutionSolution

The network of parallels and meridians is the graticule (1 mark).

Answer: (B)

Example 2: Developable surface · 2 marks · Very short answerBoard level

Why is a globe called a non-developable surface? (2 marks)

Try it first, then show the solutionSolution

It cannot be flattened without shrinking, breaking or creasing (1 mark).
So any flat map has some distortion (1 mark).

Answer: A globe cannot be flattened into a plane without shrinking, breaking or creasing, so transferring its graticule to a flat sheet always causes distortion.

Example 3: Need for projection · 3 marks · Short answerHarder board level

Give three reasons why a globe cannot replace maps and why projections are needed. (3 marks)

Try it first, then show the solutionSolution

Globe is expensive and hard to carry (1 mark).
Cannot show minor details (1 mark).
Difficult to compare two regions, so a flat map with a projection is needed (1 mark).

Answer: A globe is expensive and difficult to carry, it cannot show minor details, and comparing two regions on it is hard. A flat map is therefore needed, and a map projection transfers the graticule from the globe to the plane while preserving the property that matters most.

Example 4: Assertion and reason: distortion · 1 mark · Assertion-reasonHarder board level

Assertion (A): Distortion in a projection increases with distance from the point or line of contact.
Reason (R): Light projected from the centre of the globe falls more obliquely away from the contact.
(A) Both true, R explains A
(B) Both true, R does not explain A
(C) A true, R false
(D) A false, R true

Try it first, then show the solutionSolution

The chapter says the image is distorted away from the contact and distortion grows with distance (1 mark).

Answer: (A)

Example 5: HOTS: choose the property · 5 marks · Long answerHOTS / competency

State which global property you would preserve, and which basis of classification you would use, for (i) comparing the areas of crop regions, (ii) plotting a ship's route with a straight bearing line, (iii) preserving the shape of small coastlines. Explain why no single projection can serve all three. (5 marks)

Try it first, then show the solutionSolution

(i) Equal area (homolographic) property (1 mark).
(ii) True direction or bearing, as in azimuthal or Mercator-type projections (1 mark).
(iii) Orthomorphic (true shape) property (1 mark).
Each is a global property (1 mark).
The globe is non-developable, so preserving all properties together is impossible (1 mark).

Answer: (i) Comparing areas needs an equal-area (homolographic) projection. (ii) A straight line of constant bearing needs a projection that preserves direction. (iii) Preserving small shapes needs an orthomorphic projection. These are different global properties. Since the globe is a non-developable surface, a flat map cannot preserve distance, shape, area and direction at once, so a projection is chosen for the property needed.

Where students lose marks in Map Projections: Need, Distortion, Elements of a Projection and Classification

The slips examiners see most often, and what to write instead.

Mistake: Treating graticule as the scale
Terms confused.
Wrong working
Graticule shows distance on the map.
Right working
Graticule is the network of parallels and meridians.
Do this: Define at the start.
Usually costs: 1 mark.
Mistake: Calling globe a developable surface
Surface word misread.
Wrong working
Globe can be developed.
Right working
Globe is non-developable; cone, cylinder, plane are developable.
Do this: Link with distortion.
Usually costs: 1 mark.
Mistake: Claiming a projection keeps all properties
Overstating.
Wrong working
The best projection is correct in all respects.
Right working
Only one property or a compromise can be kept.
Do this: Say "chosen for a purpose".
Usually costs: 1 mark.

Exam tips

Define graticule and projection in the first line.
Classify with a table of four bases.
Always state that every flat map distorts.

Practice questions on Map Projections: Need, Distortion, Elements of a Projection and Classification

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
A projection in which light is placed at the centre of the globe is called:
(A) stereographic
(B) orthographic
(C) gnomonic
(D) conical
Hint
Centre.
Answer
(C)
Q2 · 2 marks · Very short answerBoard level
Name the three developable surfaces used in projections. (2 marks)
Hint
Cylinder, cone, plane.
Answer
Cylindrical, conical and zenithal (a plane).
Q3 · 3 marks · Short answerHarder board level
Distinguish between equal area and orthomorphic projections. (3 marks)
Hint
Area versus shape.
Answer
An equal-area (homolographic) projection keeps areas correct, while an orthomorphic projection keeps shapes correct, usually at the cost of area. No projection can preserve both fully.
Q4 · 3 marks · Short answerHarder board level
Describe parallels and meridians as elements of a projection. (3 marks)
Hint
Circles and semicircles.
Answer
Parallels are circles parallel to the equator, unequal in length, ranging from 0 to 90 degrees N and S. Meridians are semicircles from pole to pole, all meeting at the poles, with the Greenwich meridian (0 degrees) as reference. On a plane they become straight or curved intersecting lines.
Q5 · 4 marks · Short answerHOTS / competency
A student says "a good projection keeps distance, shape, area and direction all correct". Evaluate the statement and give the reason for your view. (4 marks)
Hint
Non-developable.
Answer
The statement is not correct. The globe is a non-developable surface, so the graticule cannot be put on a plane without distortion. A projection preserves one or two properties, for example area or direction, and distorts the others, so one is chosen for the map's purpose.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.What is a graticule?Show answer
The network of parallels and meridians.
2.Which projection source puts light at the centre?Show answer
Gnomonic.
3.What does homolographic mean?Show answer
Equal area.
4.Which meridian is the reference?Show answer
Greenwich, 0 degrees.

Map Projections: Need, Distortion, Elements of a Projection and Classification: frequently asked questions

What is a reduced earth?

A model of the earth at a reduced scale on which the graticule is drawn.

What is an oblique projection?

One in which the developable surface touches between the pole and the equator.

Are cylindrical projections in the 2026-27 practical?

CBSE limits the practical to the conical with one standard parallel and Mercator's projection.