Surveying Multiple Choice Questions on “Balancing the Traverse”.
1. Which of the following implies the correct set of methods employed for balancing the traverse?
a) Bowditch’s method, Transit method
b) Bowditch’s method, Graphical method
c) Axis method, Transit method, Gale’s method, Co-ordinate method
d) Bowditch’s method, Axis method, Graphical method, Transit method
Answer: d
Clarification: Bowditch’s and Transit method involves the usage of correction of latitude and departure formulae. Graphical method uses Bowditch’s formula for solving graphically whereas Axis method is used in case of length corrections which are having accurate angles.
2. Angles are less affected by the corrections applied due to the Transit method than Bowditch’s method.
a) True
b) False
Answer: a
Clarification: Due to distribution of total error in latitudes and departures in equal proportions, it is less affected by the corrections applied.
3. Which of the following method doesn’t require the calculation of latitudes and departures?
a) Graphical method
b) Axis method
c) Bowditch’s method
d) Transit method
Answer: a
Clarification: Since Graphical method involves a rough calculation and plotting of traverse directly from the field notes, it is not necessary for calculating latitudes and departures.
4. Balancing methods can be applied only when________
a) Survey forms a closed triangle traverse
b) Survey forms an irregular shaped traverse
c) Survey forms a closed polygon traverse
d) Survey forms a closed circular traverse
Answer: c
Clarification: While traversing, in most of the cases, the traverse will be closed by polygon. It is the only way of applying corrections for latitudes and departures i.e., ∑L=0 and ∑D=0 and for eradicating closing error.
5. Which method can also be known as Compass rule?
a) Transit method
b) Bowditch’s method
c) Graphical method
d) Axis method
Answer: b
Clarification: Due to the equal precision of the linear and angular measurements, it can be termed as compass rule.
6. Bowditch method can be applied even linear and angular measurements are not precise.
a) True
b) False
Answer: b
Clarification: Bowditch method can be applied only when linear and angular measurements are precise and so the total error can be distributed in proportions.
7. In order to complete traverse computations, which of the following steps is to be carried out first?
a) Adjusting interior angles
b) Calculating ∑L and ∑D
c) Calculating bearings of the angles
d) Applying corrections
Answer: a
Clarification: A Traverse computation involves a lot of procedure which requires accurate values for further processing. So, first we need to check and adjust the interior angles for continuing the remaining process.
8. Sum of interior angles must be equal to____________
a) (2n/4) right angles
b) (2n*4) right angles
c) (2n+4) right angles
d) (2n-4) right angles
Answer: d
Clarification: The check applied for finding the sum of interior angles is equal to (2n-4) right angles. Similarly, the check for exterior angles is equal to (2n+4) right angles.
9. Independent co-ordinates can be calculated by using___________
a) Geometric co-ordinates
b) Cylindrical co-ordinates
c) Consecutive co-ordinates
d) Spherical co-ordinates
Answer: c
Clarification: The consecutive co-ordinates which are obtained from the latitudes and departures will be able to derive independent co-ordinates.
10. Among the following, the most commonly used method of balancing a traverse is_________
a) Graphical method
b) Transit method
c) Axis method
d) Bowditch’s method
Answer: d
Clarification: Due to the precision of angular and linear measurements obtained by Bowditch’s method, it is more commonly used, but Transit method will be able to deliver less affected measurements due to corrections applied. Axis and Graphical methods can be applied whenever rough measurements are necessary.
11. Calculate the correction for departure of BC, using Bowditch’s rule.
| Line | Length (m) | Consecutive co-ordinates | |
|---|---|---|---|
| Latitude | Departure | ||
| AB | 121.87 | +225.87 | -228.92 |
| BC | 199.85 | -268.25 | +326.62 |
| CA | 245.57 | +43.31 | -98.69 |
a) 362.969
b) 326.969
c) 326.696
d) 323.969
Answer: b
Clarification: Total error in departure = -228.92 + 326.62 – 98.69 = -0.99
Perimeter of traverse = 114.99 + 217.57 + 319.31 = 567.29 m
Correction for departure of AB = length of AB * total error in departure / perimeter of traverse = 199.85 * -0.99 / 567.29 = -0.349 m. Error is negative then correction is positive i.e., correction = 326.62 + 0.349 = 326.969.
12. Using transit method, calculate the correction for latitude of BC.
| Line | Length (m) | Consecutive co-ordinates | |
|---|---|---|---|
| Latitude | Departure | ||
| AB | 125.91 | -264.97 | +50.65 |
| BC | 198.57 | +182.96 | -104.62 |
| CA | 229.88 | +79.62 | +59.77 |
a) 184.78
b) 183.789
c) 185.879
d) 183.987
Answer: b
Clarification: Total error in latitude = -264.97 + 182.96 + 79.62 = -2.39
Total perimeter of traverse = 125.91 + 198.57 + 229.88 = 554.36 m
Sum of latitudes = 264.97 + 182.96 + 79.62 = 527.55
Now, correction for latitude of BC = latitude of BC * total error in departure / sum of latitudes = 182.96 * (- 2.39) / 527.55 = – 0.829 m. If error is negative, correction is positive
Corrected departure = 182.96 + 0.829 = 183.789.