29 extra multiple-choice questions for Map Projection (12th Standard Geography, Samacheer Kalvi), beyond the ones printed in the textbook — each with the correct option highlighted and a clear, worked explanation. Free to read in English and Tamil.
Q1
When the latitudes and longitudes of the globe are represented on a flat sheet of paper, the network thus formed is called
- A. Developable surface
- B. Standard parallel
- C. GraticuleCorrect
- D. Line of tangency
Explanation. A map projection represents the latitudes and longitudes of the globe on a flat sheet of paper, and the network of lines formed in this way is called the graticule.
Q2
Which one of the following is NOT one of the criteria the lesson uses to classify map projections?
- A. Method of construction
- B. Developable surface used
- C. Scale of the mapCorrect
- D. Position of light source
Explanation. Map projections are classified on four criteria: method of construction, developable surface used, projection properties and position of light source. The scale of the map is not one of them.
Q3
Perspective projections are made with the help of
- A. mathematical calculations on an assumed developable surface
- B. the shadow cast from an illuminated globe on to a developable surfaceCorrect
- C. a protractor and a pair of compasses only
- D. the line of tangency of a cone at two parallels
Explanation. Perspective projections are made with the help of the shadow cast from an illuminated globe on to a developable surface. In non-perspective projections the surface is only assumed and construction uses mathematical calculations.
Q4
Assertion (A): Cylindrical projection is suitable for showing equatorial regions.
Reason (R): The length of the equator on the cylinder is equal to the length of the equator on the globe.
- A. Both A and R are true and R is the correct explanation of ACorrect
- B. Both A and R are true but R is not the correct explanation of A
- C. A is true but R is false
- D. A is false but R is true
Explanation. The lesson states that the length of the equator on the cylinder equals the length of the equator, and therefore cylindrical projection is suitable for showing equatorial regions. R explains A.
Q5
Which one of the following is NOT a normal cylindrical projection?
- A. Mercator projection
- B. Cassini projectionCorrect
- C. Lambert's Cylindrical Equal Area projection
- D. Miller cylindrical projection
Explanation. Normal cylindrical projections, with the line of tangency at the equator, include Equirectangular, Mercator, Lambert's Cylindrical Equal Area, Gall's Stereographic and Miller. Cassini is a transverse projection, tangent to a meridian.
Q6
The oblique cylindrical projection consists only of the
- A. Oblique Mercator projectionCorrect
- B. Transverse Mercator projection
- C. Equirectangular projection
- D. Cassini projection
Explanation. In an oblique cylindrical projection the cylinder has its line of tangency to some other point on the globe. The lesson says it consists only of the Oblique Mercator projection.
Q7
In a transverse cylindrical projection, the cylinder has its line of tangency to
- A. the equator
- B. a meridianCorrect
- C. one of the poles
- D. two standard parallels
Explanation. A cylindrical projection is transverse when the cylinder has its line of tangency to a meridian. It includes the Cassini and Transverse Mercator projections. Tangency at the equator gives the normal type.
Q8
Conical projection is most suitable for representing
- A. equatorial regions
- B. polar areas
- C. middle latitudesCorrect
- D. the whole globe at one time
Explanation. A conical projection is visualised as a cone placed on the globe, tangent at some parallel. It is suitable for representing middle latitudes and shows only one hemisphere at a time.
Q9
Consider the following statements about conical projection:
1. Parallels appear as arcs.
2. Meridians appear as straight lines that converge to the same point.
3. It can show the northern and southern hemispheres at the same time.
Which of the statements given above is/are correct?
- A. 1 only
- B. 1 and 2 onlyCorrect
- C. 2 and 3 only
- D. 1, 2 and 3
Explanation. After the cone is cut along a meridian and unfolded, parallels appear as arcs and meridians as straight lines converging to one point. A conical projection represents only one hemisphere, northern or southern, at a time.
Q10
In a secant conical projection, when the cone is not big enough to cover the curvature of the earth, it
- A. touches the globe at only one parallel
- B. intersects the earth twice at two parallelsCorrect
- C. touches the globe at one of the poles
- D. touches the globe along a meridian
Explanation. In the secant type the cone is not big enough to cover the earth's curvature, so it intersects the earth twice, at two parallels (two standard parallels). In the tangent type it touches only one parallel.
Q11
In a zenithal (azimuthal) projection, the parallels are seen as
- A. concentric circlesCorrect
- B. straight lines
- C. arcs of a cone
- D. parallel lines equal to the equator
Explanation. In a zenithal projection the tangent point is the centre of a circular map; meridians through the centre are straight lines and the parallels are seen as concentric circles. It suits polar areas.
Q12
When the plane of a zenithal projection is tangent to a point between a pole and the equator, the aspect is called
- A. equatorial zenithal
- B. polar zenithal
- C. oblique zenithalCorrect
- D. normal zenithal
Explanation. The aspects of zenithal projection are equatorial (plane tangent to a point on the equator), oblique (tangent to a point between a pole and the equator) and polar (tangent to one of the poles).
Q13
Equal area projections are also known as
- A. orthomorphic projections
- B. homolographic projectionsCorrect
- C. equidistant projections
- D. gnomonic projections
Explanation. Equal area projections are also known as homolographic projections. The areas of different parts of the earth are correctly represented by them. True shape projections are called orthomorphic.
Q14
In the Polar Zenithal Equi-distant projection, the parallels are drawn
- A. at true distances from one anotherCorrect
- B. at distances that decrease toward the edge of the map
- C. as arcs of a cone
- D. as straight lines equal in length to the equator
Explanation. In the Polar Zenithal Equi-distant projection the pole is the centre, parallels are concentric circles and the spacing between the parallels represents true distances. It is used for maps of polar areas.
Q15
Which statement about true scale (equidistant) projections is correct according to the lesson?
- A. They keep the correct scale throughout the map.
- B. No projection can keep the correct scale throughout; it can be kept only along some parallels or meridians.Correct
- C. They keep the correct scale only at the centre of the map.
- D. They show true shapes of all parts of the earth.
Explanation. Projections that maintain correct scale are called true scale projections. However, no projection can maintain the correct scale throughout; correct scale can only be maintained along some parallels or meridians.
Q16
In which projection is the source of light placed at the centre of the globe?
- A. Stereographic projection
- B. Orthographic projection
- C. Gnomonic projectionCorrect
- D. Equidistant projection
Explanation. In classification by position of light source, the gnomonic projection is obtained when the source of light is placed at the centre of the globe.
Q17
Match the projection with the position of its light source:
a. Gnomonic - 1. At infinity from the globe
b. Stereographic - 2. At the centre of the globe
c. Orthographic - 3. At the periphery of the globe, diametrically opposite the point of contact
- A. a-2, b-3, c-1Correct
- B. a-1, b-3, c-2
- C. a-3, b-2, c-1
- D. a-2, b-1, c-3
Explanation. Gnomonic: light at the centre of the globe. Stereographic: light at the periphery, diametrically opposite the point where the developable surface touches. Orthographic: light at infinity, opposite that point.
Q18
The Cylindrical Equal Area projection was devised by
- A. Marinus of Tyre
- B. J.H. LambertCorrect
- C. Mercator
- D. Cassini
Explanation. The Cylindrical Equal Area projection, also called Lambert's Cylindrical Equal-area projection, was devised by J.H. Lambert in 1772. It is a normal perspective projection on a cylinder tangent at the equator.
Q19
In the Cylindrical Equal Area projection, the distance between the parallels
- A. remains the same throughout the map
- B. increases toward the poles
- C. decreases toward the polesCorrect
- D. is equal to the distance between meridians
Explanation. In the Cylindrical Equal Area projection, the distance between parallels decreases toward the poles, while the meridians are equally spaced. Parallels and meridians are straight lines meeting at right angles.
Q20
Assertion (A): In the Cylindrical Equal Area projection, the scale is true only along the equator.
Reason (R): On this projection the other parallels are drawn longer than the corresponding parallels on the globe.
- A. Both A and R are true and R is the correct explanation of ACorrect
- B. Both A and R are true but R is not the correct explanation of A
- C. A is true but R is false
- D. A is false but R is true
Explanation. The equator on this projection has the same length as on the globe, but every other parallel is drawn equal to the equator and so is longer than on the globe. Hence scale is true only along the equator.
Q21
The Cylindrical Equi-distant projection is believed to have been invented by
- A. J.H. Lambert
- B. Marinus of TyreCorrect
- C. Gall
- D. Miller
Explanation. The Cylindrical Equi-distant projection is a projection on to a cylinder tangent to the equator. It is believed to have been invented by Marinus of Tyre around C.E. 100.
Q22
In the Cylindrical Equi-distant projection, the meridians are
- A. curved lines converging at the poles
- B. straight parallel lines, equally spaced and half as long as the equatorCorrect
- C. straight lines radiating from the pole
- D. straight lines equal in length to the equator
Explanation. In the Cylindrical Equi-distant projection, meridians are straight parallel lines, equally spaced and half as long as the equator, while the poles and parallels are straight lines equal to the equator.
Q23
Maps on the Cylindrical Equi-distant projection are used for general purposes only because the projection
- A. is neither equal area nor orthomorphicCorrect
- B. shows only one hemisphere at a time
- C. has its line of tangency at a pole
- D. is a gnomonic projection
Explanation. Since the Cylindrical Equi-distant projection is neither equal area nor orthomorphic, the lesson says maps drawn on it are used for general purposes only.
Q24
In Example 10.2 (Cylindrical Equi-distant projection, interval 30°), into how many parts is the central meridian divided to draw the parallels?
- A. 3
- B. 6Correct
- C. 12
- D. 18
Explanation. A meridian on the globe is subtended by 180°. With parallels at an interval of 30°, the central meridian is divided into 180/30 = 6 parts.
Q25
To draw meridians at an interval of 30° for the whole globe on a cylindrical projection, the equator line is divided into how many equal parts?
- A. 6
- B. 9
- C. 12Correct
- D. 24
Explanation. The equator represents 360° of longitude. For meridians at 30° interval it is divided into 360/30 = 12 equal parts, as in Examples 10.1 and 10.2.
Q26
The Polar Zenithal Equal Area projection is also known as
- A. Lambert's Equal Area projectionCorrect
- B. Mercator projection
- C. Cassini projection
- D. Gnomonic projection
Explanation. The Polar Zenithal Equal Area projection was devised by J.H. Lambert and is also known as Lambert's Equal Area projection. It is used for political and distribution maps of polar regions.
Q27
Consider the following statements about the Polar Zenithal Equal Area projection:
1. The pole is a point forming the centre of the projection.
2. The meridians are straight lines radiating from the pole with correct angular distance between them.
3. The scale along the parallels decreases away from the centre of the projection.
Which of the statements given above is/are correct?
- A. 1 only
- B. 1 and 2 onlyCorrect
- C. 2 and 3 only
- D. 1, 2 and 3
Explanation. The pole is the centre point, the parallels are concentric circles and the meridians radiate from the pole with correct angular distance. The scale along the parallels increases, not decreases, away from the centre.
Q28
In Example 10.3 (Polar Zenithal Equal Area projection), the circle drawn with centre N and radius equal to CB represents the
- A. 60° parallel
- B. 30° parallel
- C. 0° parallelCorrect
- D. 90° parallel
Explanation. With centre N, the circle of radius CF represents the 60° parallel, radius CE the 30° parallel and radius CB the 0° parallel. The point N itself is the 90° parallel (the pole).
Q29
In a Polar Zenithal Equi-distant projection, the number of parallel intervals is found as 90 divided by the interval. How many concentric circles are needed for an interval of 15°?
- A. 3
- B. 4
- C. 6Correct
- D. 12
Explanation. Example 10.4 finds the number of intervals as 90/30 = 3 for a 30° interval. For a 15° interval, as in exercise 4, it is 90/15 = 6, so six concentric circles are drawn around the pole.
