All Free Civil Engineering MCQs with Answers

• A. The elevation of a benchmark
• B. The magnetic declination of a compass
• C. The position of the instrument station
• D. The area of a plotted polygon

Explanation: Resection locates the occupied plane table station by sighting to points whose positions are already known.

• A. It eliminates the need for any control points
• B. It requires no centering or levelling
• C. It works without line of sight to the target
• D. It electronically measures distances and angles

Explanation: A total station combines electronic angle measurement with electronic distance measurement and data processing.

• A. 5,000 square metres
• B. 3,000 square metres
• C. 1,500 square metres
• D. 10,000 square metres

Explanation: The plot has a length of 100 m and a width of 50 m. Its area is therefore 100 × 50 = 5,000 square metres.

• A. It levels the instrument at each station
• B. It establishes the required relation between instrument axes
• C. It focuses the telescope on a particular staff
• D. It sets the initial reading of the horizontal circle

Explanation: Permanent adjustment establishes and maintains the correct geometric relationships among the theodolite axes.

• A. 208.675 m
• B. 209.125 m
• C. 213.025 m
• D. 213.675 m

Explanation: Reduced level is found by subtracting the foresight from the height of instrument: 210.850 minus 2.175 equals 208.675 m.

• A. To determine magnetic declination
• B. To calculate the traverse bearing
• C. To increase the contour interval
• D. To eliminate errors from unequal sight lengths

Explanation: Reciprocal levelling uses observations from both sides of an obstacle, so errors caused by collimation, curvature and refraction are…

• A. 308°20′
• B. 128°20′
• C. 231°40′
• D. 51°40′

Explanation: The back bearing is obtained by adding 180 degrees when the fore bearing is less than 180 degrees. Thus, 128°20′ plus 180° equals 308°20′.

• A. 50.0 m north and 86.6 m east
• B. 86.6 m north and 50.0 m east
• C. 86.6 m south and 50.0 m east
• D. 50.0 m south and 86.6 m west

Explanation: For a bearing measured from north, latitude equals L cos 30 degrees and departure equals L sin 30 degrees.

• A. Random error
• B. Gross error
• C. Systematic error
• D. Personal accidental error

Explanation: A consistent instrument constant produces a systematic error because its effect follows a regular pattern and can often be determined or…

• A. Horizontal equivalent
• B. Reduced distance
• C. Contour gradient
• D. Vertical interval

Explanation: The difference in elevation between consecutive contour lines is called the contour interval or vertical interval.

• A. Around one accessible station
• B. Only on the opposite side of an obstacle
• C. Along a long closed traverse
• D. At points with unknown magnetic declination

Explanation: In radiation, rays are drawn from one occupied plane table station to the detail points, and distances are measured from that station.

• A. To make the vertical axis exactly vertical
• B. To place the instrument over the survey station
• C. To remove error of eccentricity permanently
• D. To set the telescope line perpendicular to the horizontal axis

Explanation: Centring places the vertical axis of the theodolite directly over the ground station.

• A. Magnetic bearing
• B. Atmospheric pressure
• C. Relative elevation or height difference
• D. Instrument bubble sensitivity

Explanation: The change in apparent position of an image between overlapping photographs is parallax, and its magnitude is related to the relative…

• A. Increasing the difference between sight lengths
• B. Using a shorter staff at each point
• C. Taking several foresights at one point
• D. Taking equal sight lengths on both sides

Explanation: Equal backsight and foresight distances make the collimation error equal in both readings, so it cancels in the difference.

• A. To make the vertical axis truly vertical
• B. To measure the length of the survey line
• C. To determine the magnetic bearing
• D. To remove local attraction from the compass

Explanation: Levelling makes the vertical axis of the instrument truly vertical and allows the horizontal circle to represent horizontal directions.

• A. Determine the height of the instrument
• B. Increase the angle-reading precision
• C. Measure the staff intercept directly
• D. Eliminate the need for centring

Explanation: The repetition method measures an angle several times successively and reads the accumulated angle, reducing the relative effect of…

• A. Radial traverse
• B. Open traverse
• C. Closed traverse
• D. Chain traverse

Explanation: A closed traverse provides geometric or coordinate closure because its endpoint is known.

• A. L divided by cos θ
• B. L sin θ
• C. L tan θ
• D. L cos θ

Explanation: Latitude is the north-south component of a line, so it equals L cos θ when the bearing is measured from north.

• A. Horizontal equivalent
• B. Contour interval
• C. Vertical interval
• D. Contour gradient

Explanation: The horizontal equivalent is the horizontal distance between consecutive contour lines.

• A. Weight of a suspended measuring tape
• B. Travel time or phase change of electromagnetic waves
• C. Difference between two staff readings
• D. Deflection of a magnetic needle

Explanation: EDM instruments send electromagnetic waves to a target and determine distance from their travel time or phase difference.