SSC JE Exam - prismatic compass compass traversing bearings local attraction plane table surveying Question Bank with Options

1. What is the 'object' of compass traversing?

A) To determine the elevation of points

B) To measure distances between points

C) To establish a framework of control points by measuring angles and distances

D) To plot detailed topography

2. If the forward bearing of a line AB is N 50° E and the backward bearing of BA is S 50° W, what can be concluded?

A) Local attraction is present at A

B) Local attraction is present at B

C) No local attraction is present

D) The bearings are incorrectly measured

3. What is the primary limitation of plane table surveying in hilly or obstructed terrain?

A) Difficulty in leveling the table

B) Inability to plot details accurately

C) Requires extensive office work

D) Limited visibility between stations

4. Which of the following is a common type of alidade used in plane table surveying?

A) Telescopic alidade

B) Plain alidade

C) Both a and b

D) None of the above

5. In prismatic compass surveying, what does the 'vernier' scale usually measure?

A) Vertical distances

B) Horizontal angles or bearings

C) Elevations

D) Magnetic dip

6. What is the main purpose of checking the 'fore and back bearings' of a line in compass traversing?

A) To determine the length of the line

B) To calculate the area enclosed by the traverse

C) To detect and correct for local attraction

D) To measure the magnetic declination

7. Which method is used to orient the plane table when it is set up at an unknown station, but the directions of at least three known points are visible?

A) Radiation

B) Intersection

C) Traversing

D) Resection

8. What is the 'dip' of a magnetic needle?

A) The horizontal angle between true north and magnetic north

B) The vertical angle the needle makes with the horizontal plane

C) The deviation of the needle from the north due to local attraction

D) The error in reading the scale

9. In compass traversing, if the sum of interior angles of a closed traverse is calculated to be 350°, what is the error in the angles?

A) 0°

B) 10°

C) 20°

D) The calculated sum is correct

10. What is the primary advantage of using a plane table over a theodolite for certain surveys?

A) Higher precision in angle measurement

B) Direct plotting reduces cumulative errors

C) Better for establishing control points

D) Less affected by atmospheric conditions

11. If the magnetic declination is 10° West, and the magnetic bearing of a line is S 20° W, what is its true bearing?

A) S 10° W

B) S 30° W

C) N 20° W

D) N 10° W

12. What is the purpose of the 'spirit level' on a plane table?

A) To measure horizontal angles

B) To ensure the table is perfectly horizontal

C) To center the table over a station

D) To orient the table

13. Which method of plane table surveying is used to plot details of an area from a single station?

A) Traversing

B) Intersection

C) Radiation

D) Resection

14. What is the 'three-point problem' in plane table surveying?

A) Locating a point from three known points

B) Orienting the plane table at an unknown station using three known stations

C) Determining the bearing of three consecutive lines

D) Plotting three objects from a single station

15. In plane table surveying, the 'two-point problem' is a specific case of:

A) Radiation

B) Intersection

C) Resection

D) Traversing

16. What is the main difference between a prismatic compass and a surveyor's compass regarding sighting?

A) Prismatic compass has a mirror, surveyor's compass does not

B) Prismatic compass has a glass, surveyor's compass does not

C) Prismatic compass allows sighting and reading simultaneously, surveyor's compass requires separate sighting and reading

D) Surveyor's compass is more accurate

17. A line has a WCB of 315°. What is its Reduced Bearing (RB)?

A) N 45° W

B) N 45° E

C) S 45° W

D) S 45° E

18. If the forward bearing of line AB is 120°, what is its backward bearing?

A) 30°

B) 120°

C) 240°

D) 300°

19. What is the 'index error' in a prismatic compass?

A) Error due to local attraction

B) Error due to improper sighting

C) Error due to the line of sight not being parallel to the zero line of the graduation

D) Error due to magnetic declination

20. Which of the following can cause errors in plane table surveying?

A) Inaccurate sighting

B) Improper orientation

C) Wind causing vibration

D) All of the above

21. In plane table traversing, what is the primary requirement for orienting the table?

A) A known direction (e.g., magnetic north or a previous line)

B) The exact elevation of the station

C) A stable tripod

D) A long measuring tape

22. What is the 'Bevel Protractor' used for in conjunction with the Alidade?

A) To measure distances

B) To draw vertical lines

C) To measure horizontal angles

D) To center the instrument

23. What is a major advantage of plane table surveying?

A) High accuracy for large-scale projects

B) Direct plotting of field data reduces errors

C) Less affected by magnetic anomalies

D) Suitable for dense forest areas

24. The 'Resection' method in plane table surveying is used to determine:

A) The location of inaccessible points

B) The orientation of the plane table when the instrument is set up at an unknown station

C) The direction of magnetic north

D) The elevation of a point

25. Which method of plane table surveying is used to establish a series of connected points forming a traverse?

A) Radiation

B) Intersection

C) Traversing

D) Resection

26. What does 'orientation' of the plane table mean?

A) Centering the plane table over a station

B) Leveling the plane table

C) Setting up the plane table so that the map is in the same relative position as the ground

D) Drawing lines of sight to objects

27. What is the 'Plumb Bob' used for in plane table surveying?

A) To orient the plane table

B) To center the plane table over a station

C) To measure vertical distances

D) To draw parallel lines

28. What is the 'Alidade' used for in plane table surveying?

A) To level the plane table

B) To hold the drawing paper

C) To sight objects and draw lines of sight on the drawing

D) To measure distances accurately

29. The 'Intersection' method of plane table surveying is best suited for:

A) Open terrain with few stations

B) Areas with inaccessible stations

C) Establishing a traverse network

D) Detailed contour mapping

30. In the 'Radiation' method of plane table surveying, how are points plotted?

A) By drawing lines of sight from two known stations

B) By drawing lines of sight from a single station to the object

C) By measuring angles between lines of sight from two stations

D) By establishing a closed loop of stations

31. Which of the following is NOT a method of plane table surveying?

A) Radiation

B) Progression

C) Traversing

D) Intersection

32. What is the main purpose of 'plane table surveying'?

A) To measure precise vertical angles

B) To plot the survey stations and traverse lines directly in the field

C) To determine the elevation of inaccessible points

D) To establish precise control points for large-scale mapping

33. Which instrument is typically used in conjunction with a prismatic compass for taking measurements in the field?

A) Theodolite

B) Level

C) Chain or Tape

D) Abney level

34. What is the theoretical difference between the forward and backward bearing of a line if there is no local attraction?

A) 0°

B) 90°

C) 180°

D) 360°

35. What is the resultant bearing of a line whose Reduced Bearing is S 60° W?

A) 60°

B) 120°

C) 240°

D) 300°

36. In Whole Circle Bearing (WCB), what is the bearing of a line pointing directly West?

A) 90°

B) 180°

C) 270°

D) 0°

37. What is the primary advantage of using a prismatic compass over a surveyor's compass?

A) It is lighter and more portable

B) It allows for sighting and reading the bearing simultaneously

C) It measures angles more accurately

D) It is unaffected by local attraction

38. If the magnetic declination is 5° East, and the magnetic bearing of a line is N 40° E, what is its true bearing?

A) N 35° E

B) N 45° E

C) S 40° E

D) S 5° E

39. What is the difference between the true bearing and the magnetic bearing of a line called?

A) Local attraction

B) Dip

C) Magnetic declination

D) Azimuth error

40. What is the purpose of 'checking the bearings' in compass traversing?

A) To increase the speed of surveying

B) To detect and correct for local attraction

C) To measure the perimeter of the area

D) To determine the magnetic declination accurately

41. If the forward bearing of a line AB is observed as N 30° E and the backward bearing of BA is observed as S 28° E, what is the likely presence of?

A) No local attraction

B) Local attraction at station A

C) Local attraction at station B

D) Local attraction at both A and B

42. How can the effect of local attraction be detected during compass traversing?

A) By comparing the forward and backward bearings of a line

B) By using a clinometer to measure vertical angles

C) By measuring the distance to the object multiple times

D) By checking the leveling of the instrument

43. Which of the following is a common source of local attraction?

A) A large body of water

B) A steel bridge or iron ore deposit

C) A dense forest area

D) High altitude

44. What is 'local attraction' in prismatic compass surveying?

A) The tendency of the compass needle to point to true north

B) The deviation of the compass needle from the magnetic north due to nearby magnetic materials

C) The error caused by imprecise leveling of the instrument

D) The parallax error when reading the scale

45. In Reduced Bearing (RB) system, if a line has a bearing of N 45° E, what is its Whole Circle Bearing (WCB)?

A) 45°

B) 135°

C) 225°

D) 315°

46. Which type of bearing is measured clockwise from the North direction?

A) Reduced Bearing (RB)

B) Whole Circle Bearing (WCB)

C) Quadrant Bearing (QB)

D) Azimuth

47. What is a 'bearing' in the context of a prismatic compass?

A) The angle measured from the north or south line to the object

B) The distance from the instrument to the object

C) The elevation of the object above sea level

D) The magnetic declination at a specific location

48. In prismatic compass surveying, what does 'traversing' refer to?

A) Measuring the height of a building

B) Establishing a network of control points by measuring angles and distances

C) Determining the magnetic declination

D) Plotting the topography of a small area

49. What is the primary function of a prismatic compass in surveying?

A) To measure vertical angles

B) To measure horizontal angles and bearings

C) To determine elevations of points

D) To measure distances between points

prismatic compass compass traversing bearings local attraction plane table surveying - Question Bank