Examination Practice Questions And

Illinois GIS Technician Certification Examination Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

Q1. What is the primary purpose of a Geographic Information System (GIS)?

• To generate random spatial data
• To capture, store, analyze, and visualize spatial information
• To replace cartographers
• To predict all natural disasters

Rationale: GIS integrates hardware, software, and data to manage and

analyze spatially referenced information.Q2. Which coordinate system uses latitude and longitude?

• State Plane

B. UTM

• Geographic Coordinate System (GCS) 1 / 4

• Lambert Conformal Conic

Rationale: GCS defines locations based on angles from Earth’s center,

expressed as latitude/longitude.Q3. A shapefile consists of how many mandatory files?

• Two
• Four
• Three (.shp, .shx, .dbf)
• Five

Rationale: These three files are essential to describe geometry, index, and

attributes.

Q4. Raster data is best suited for representing:

• Parcel boundaries
• Continuous surfaces
• Roads
• Ownership parcels

Rationale: Raster excels at modeling continuous phenomena such as

elevation or temperature.Q5. Which projection minimizes distortion along a central line of latitude?

• Mercator

B. UTM

• Lambert Conformal Conic
• Stereographic 2 / 4

Rationale: The Lambert Conformal Conic preserves shape and reduces

distortion for mid-latitude regions.Q6. A map scale of 1:24,000 means:

• 1 inch equals 240 feet
• 1 unit on map equals 24,000 units on ground
• 1 meter equals 24,000 meters on map
• Map is enlarged 24,000 times

Rationale: Scale expresses the ratio of map distance to ground distance.

Q7. What is topology in GIS?

• Symbol color
• Rules governing spatial relationships
• Map style preferences
• Database design

Rationale: Topology ensures features follow defined spatial rules such as

adjacency and connectivity.

Q8. The value stored in each cell of a DEM represents:

• Vegetation type
• Elevation
• Road density
• Temperature

Rationale: DEMs store elevation values in raster format.

Q9. Which file format supports lossless GIS data compression?

A. JPEG 3 / 4

• TIFF (with LZW or ZIP compression)

C. BMP

D. GIF

Rationale: TIFF supports lossless compression suitable for raster GIS data.

Q10. Which Illinois coordinate system is commonly used for county-level mapping?

• UTM Zone 15

B. GCS NAD27

• Illinois State Plane (NAD83)
• Web Mercator

Rationale: Illinois agencies commonly use State Plane coordinates based

on NAD83.

Q11. Metadata describes:

• Symbol colors
• Information about the data
• Map labels
• User passwords

Rationale: Metadata includes source, accuracy, date, scale, and processes

used.

Q12. The process of converting raster to vector is called:

• Projecting
• Vectorization
• Geocoding
• / 4