Rambabu Palaka, Assistant Professor, BVRIT, Narsapur, Telangana State, India

SURVEYING (LEVELLING, CONTOURS, AREAS & VOLUMES)

Question Bank

1. A Level Line is a line parallel to the mean spheroidal surface of earth. 2. If the R.L. of a B.M. is 100.00 m, the back sight is 1.215 m and the foresight is 1.870 m, the R.L. of the forward station is 99.345 m. 3. The rise and fall method provides a check on the reduction of intermediate point levels. 4. With the rise of temperature, the sensitivity of a bubble tube decreases. 5 Refraction correction partially eliminates curvature correction. 6. An imaginary line lying throughout the surface of ground and preserving a constant inclination to the horizontal is known as contour gradient. 7. The suitable contour interval for a map with scale 1 : 10000 is 2 m. 8. A series of closely spaced contour lines represents a steep slope. 9. Which method of Contouring is most accurate method? Direct method of contouring 10. In direct method of contouring, the process of locating or identifying points lying on a contour is called vertical control. 11. Closed contours, with higher value inwards, represent a hillock. 12. Contour interval is the vertical distance between two consecutive contours. 13. Which of the following errors can be neutralized by setting the level midway between the two stations error due to both curvature and refraction 14. Advantage of Height of instrument method of leveling is quicker and less tedious for large number of intermediate sights 15. If the staff is not held vertical at a leveling station, the R.L. calculated from the observation would be less than true R.L. 16. The sensitivity of a bubble tube can be increased by increasing the diameter of the tube 17. The R.L. of the point A which is on the floor is 100 m and back sight reading on A is 2.455m

Rambabu Palaka, Assistant Professor, BVRIT, Narsapur, Telangana State, India

18. If the foresight reading on the point B which is on the ceiling is 2.745 m, the R.L. of point B will be 105.20 m. 19. An imaginary level surface to which all elevations are measured or referred to Datum 20. GTS Benchmarks means Great Trigonometrically Survey Benchmark 21. These benchmarks are established with very high degree of precision at regular intervals all over the country by Survey of India. 22. The line of sight defined by the optical centre of the object glass and the centre of the cross bars Height of Collimation 23. Temporary Adjustments of Level Instrument are

• Setting up a Level • Leveling of Telescope • Focusing of eye-piece • Focusing of object glass

24. The technique is used to obtain the heights of points above the line of sight such as ceilings and undersides of bridges Inverted Levelling 25. The horizontal distance between any two adjacent contours is called as Contour Equivalent or Horizontal Equivalent 26. The method gives greater accuracy than other methods other for calculating areas assumes that the irregular boundary is composed of a series of parabolic arcs Simpson's Method 27. Closed contours of decreasing values towards their centre, represent Depression or Pond 28. The method can be applied for computation of areas only if the number of ordinates is odd. Simpson's Method