UNIT II

1. What is magnetic meridian? [N/D-14]

The direction shown by a magnetic needle without being affected by any magnetic substances when the needle is suspended and balanced properly. This is known as the magnetic meridian.

2. State the three-point problem [N/D-14]

Location of the position on the plan of the station occupied by the plane table by means of observations to three well defined points, whose positions have been previously plotted on the plan.

3. Define - True bearing [M/J-15]

True bearing of a line is the angle made by the line with the true or geographical north. It is always measured in the clockwise direction with a measuring range of 0° to 360°.

4. Write any two advantages of plane table surveying. [M/J-15]

The advantages of plane table surveying are:

a) The plan is drawn at the field itself.

b) The surveyor can compare the plotted work with actual features of the area.

c) Most suitable for small scale work.

d) No great skill is required

5. Differentiate Prismatic compass from Surveyor's compass with reference to reading as well as tripod. [N/D - 15]

Prismatic compass:

In prismatic compass, the reflecting prism carries the sighting and the sighting of the object. Readings are taken simultaneously. In prismatic compass, the reflecting prism carries the sighting and the sighting of the object. Readings are taken simultaneously.

Surveyor's compass:

In surveyor’s compass, the object has to be sighted to ground to read graduation and readings are with reference to tripod. Surveyor's compass cannot be used without a tripod.

6. State any two advantages of plane table surveying? [M/J-15,N/D-15]

The plan is drawn at the field itself.

The surveyor can compare the plotted work with actual features of the area.

7. What is orientation? Why it is to be performed? [N/D-14,M/J-16]

The table is so positioned in a way that all the lines plotted will be parallel to the corresponding lines on the ground. This process is called orientation. The process connects all the ground stations and maintains the same position in the paper. Orientation is performed at every successive station. Orientation can be done by back-sighting method or by using magnetic needle.

8. List out the errors in a compass instrument. [N/D-14,M/J-16]

The errors in a compass may be caused due to:

a) Needle not straight

b) Pivot not upright

c) Needle lost magnetism

d) Pivot not sharp but dull

e) Movement of the needle not free

f) Plane of sight not vertical

g) Graduation circle not horizontal

9. What is meant by hypotenusal allowance? [N/D-14] The allowance in a measurement made on a peg ground to get the horizontal distances is called the hypotenuse allowance. This is given as 100, which is the angle of slope.

PART B

1. The bearings of the sides of a traverse ABCDE are as follows :

Line F.B B.B

AB 107015’ 287015’

BC 2200’ 20200’

CD 281030’ 101030’

DE 189015’ 9015’

EA 124045’ 304045’

Compute the interior angle of the traverse [N/D-14,N/D-15]

2. Explain briefly the following methods of solution of three point problem

(i) Besssel’s Graphical method

(ii) Trial and Error method [M/J-15, N/D-14]

3. A compass survey was carried out around a closed transverse ABCD and the

following reading were obtained

Line F.B B.B

AB 740 30’ 256010’

BC 107030’ 286010’

CD 225010’ 45010’

DE 3060 50’ 1260 10’

identify which station were affected by local attraction and determine the

correceted bearing. [N/D-14, M/J-15]

4. Find out the station affected by local attraction and work out the correceted

bearings of the lines.

Line F.B B.B

AB 1910 45’ 39030’

BC 22015’ 22200’

CD 22015’ 200030’

DE 2420 45’ 620 45’

EA 3300 15’ 1470 45’

[M/J-15]

6.

What is Resection? Explain the three point problem with illustrative diagram

[N/D-15]

7. Explain with sketches. The following methods using plane table.

(1) Radiation

(2) Intersection [A/M-13, M/J-13]

8. Explain the three point problem with illustrative diagram. [N/D-15,M/J-13]

9. Differentiate between prismatic and surveyor compass? [M/J-13, N/D-15]