This set of GIS Multiple Choice Questions & Answers (MCQs) focuses on “Digital Database in a GIS”.
1. What is the most essential component of a GIS?
a) Information Database
b) Graphical Representation
c) Satellite
d) Software
View Answer
Explanation: The information database is developed by capturing information from different sources like topographical maps, thematic maps, and cadastral maps, in analogue form, remotely sensed images in digital form and so on.
2. Location and distance are the key features in mapping geographic information. True or false?
a) True
b) False
View Answer
Explanation: Global Reference System is used to reference system location on the surface of the globe with points on a map.
3. The general technique of converting the analogue map to digital form is either by manual digitisation or by:
a) typing
b) printing
c) scanning
d) photography
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Explanation: Manual digitisation is the commonly used technique for including analogue data in a digital database.
4. Whether the unit of measurement be inches or centimetres, when associated with digitising, it is called a:.
a) Digital Unit
b) Digitiser Unit
c) Unit of Automation
d) Unit of Digitisation
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Explanation: Coverages may be digitised in digitiser units or real-world units. The digitiser is based on a type of rectangular coordinate system with its origin in the lower-left corner. On the digitiser surface, moving one inch up or down covers the same distance as moving one inch left or right.
5. A coverage can be digitised in meters, but not in:
a) kilometres
b) inches
c) centimetres
d) degrees
View Answer
Explanation: The distance represented by a degree depends upon its location on the globe which is the global reference system and not a rectangular coordinate system. Thus, a coverage can be digitised in meters, but not in degrees.
6. Coverages are not spatially referenced and cannot be displayed simultaneously using digitiser units. True or false?
a) True
b) False
View Answer
Explanation: Real world units allow multiple coverages to be shown, such as background or adjacent coverages.
7. A common step in quality assurance when initially developing a database is to compare a digitised file with it’s:
a) Referencing System
b) Database
c) Source Map
d) Real Units
View Answer
Explanation: This is most commonly done by creating an edit plot and overlaying it on a light table. If a map is digitised in real-world units, it may have been stretched and scaled so that it will no longer register accurately with the source map even if the file was digitised accurately.
8. The algorithms that perform snapping functions using a measurement of length or area are based upon:
a) Cartesian Coordinates
b) Rectangular Coordinates
c) Polar Coordinates
d) Conical Coordinates
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Explanation: The length of a line of latitude between two meridians varies with latitude, and the area is confusing when measured in square degrees.
9. Digitising staff has less to learn when they use:
a) Digital Unit
b) Digitiser Unit
c) Unit of Automation
d) Real-World Units
View Answer
Explanation: When real-world units are used, the digitising staff should understand transformation and projection concepts.
10. One cannot know whether initial digitising of tics was accurate while using:
a) Digital Unit
b) Digitiser Unit
c) Unit of Automation
d) Real-World Units
View Answer
Explanation: RMS error indicates actual tic accuracy in real-world units.
Sanfoundry Global Education & Learning Series – GIS.
To practice all areas of GIS, here is complete set of Multiple Choice Questions and Answers.