GPSC Civil Engineering (Combine Exam) Paper Solution (03-05-26) – Page 16

151) In photogrammetry, the ‘parallax bar reading’ is used to determine

1. Horizontal distance between two ground points
2. Elevation of points using stereoscopic pairs
3. Azimuth of a survey line
4. Scale of the aerial photograph

152) In the Bowditch (Compass) rule for traverse adjustment, the correction to latitude of a line is proportional to

1. Length of that line / Total perimeter of traverse
2. Latitude of that line / Arithmetic sum of all latitudes
3. Bearing of that line
4. Departure of that line / Total perimeter

153) The ‘Rock Quality Designation (RQD)’ index is used in Engineering Geology to

1. Determine the compressive strength of rock
2. Measure the porosity of rock samples
3. Classify rock mass quality based on core recovery
4. Determine the permeability of rock formations

154) In plane table surveying, the ‘three-point problem’ is solved by which of the following methods?

1. Bessel’s method
2. Trial and error (Lehmann’s method)
3. Mechanical (Tracing paper) method

Select the correct answer.

1. 1 only
2. 1 and 3 only
3. 2 and 3 only
4. 1, 2 and 3

155) In geological mapping, a ‘fault’ where the hanging wall moves up relative to the footwall is called

1. Normal fault
2. Strike-slip fault
3. Reverse (Thrust) fault
4. Oblique-slip fault

156) The ‘relief displacement’ in a vertical aerial photograph is

1. Inversely proportional to the flying height and directly proportional to the radial distance from principal point
2. Directly proportional to both flying height and height of object
3. Independent of the position of the object in the photograph
4. Inversely proportional to the height of the object

157) Consider the following statements about ‘Setting Out of Curves’ in surveying:

1. In the Rankine’s deflection angle method, the deflection angle for a chord is half the angle subtended by that chord at the centre.
2. The ‘offset from long chord’ method gives exact results for short circular curves.
3. In two-theodolite method, no linear measurements are required.

Which of the above statements are correct?

1. 1 and 2 only
2. 2 and 3 only
3. 1 and 3 only
4. 1, 2 and 3

158) In GIS, the ‘Thiessen polygon’ (Voronoi diagram) method is primarily used for

1. Contour interpolation from spot heights y
2. Distributing point data over an area (spatial interpolation of rainfall data)
3. Network analysis and shortest path determination
4. Overlay analysis of vector layers

159) In the ‘Total Station’ instrument, which of the following statements is/are correct?

1. EDM (Electronic Distance Measurement) in Total Station uses infrared or laser light waves.
2. Reflectorless Total Stations can measure distances without a prism.
3. The accuracy of angle measurement in a Total Station is typically expressed in ‘gon’ (grad) only.

Select the correct answer.

1. 1 only
2. 1 and 2 only
3. 2 and 3 only
4. 1, 2 and 3

160) Consider the following statements regarding the ‘jar test’ used in water treatment:

1. It simulates the coagulation-flocculation-sedimentation process at laboratory scale.
2. The optimum coagulant dose determined by jar test is independent of pH.
3. Rapid mixing is used during flocculation to create turbulence that aids floc growth.

Which of the statements given above is/are correct?

1. 1 only
2. 1 and 3 only
3. 2 and 3 only
4. 1, 2 and 3