# Surveying Questions and Answers – Tacheometric Surveying – Stadia Method Principle

This set of Surveying Multiple Choice Questions & Answers (MCQs) focuses on “Tacheometric Surveying – Stadia Method Principle”.

1. Horizontal distances are measured by direct methods, i.e. laying of chains or tapes on the ground.
a) True
b) False

Explanation: Generally, horizontal distances are measured by direct methods, i.e. laying of chains or tapes on the ground. These methods are not always convenient if the ground is undulating, rough, difficult and inaccessible.

2. If the ground is undulating, rough, difficult and inaccessible. Under these circumstances _________ methods are used to obtain distances.
a) Direct methods
b) Indirect methods
c) Chain surveying
d) Tacheometry

Explanation: Generally, horizontal distances are measured by direct methods, i.e. laying of chains or tapes on the ground. These methods are not always convenient if the ground is undulating, rough, difficult and inaccessible. Under these circumstances, indirect methods are used to obtain distances.

3. Which of the following is an indirect method of surveying?
a) Chain surveying
b) Tacheometry
c) Countouring
d) All of the mentioned

Explanation: Generally, horizontal distances are measured by direct methods, i.e. laying of chains or tapes on the ground. These methods are not always convenient if the ground is undulating, rough, difficult and inaccessible. Under these circumstances, indirect methods are used to obtain distances. One such method is “Tacheometry”.

4. Using tacheometric methods, elevations can also be determined.
a) True
b) False

Explanation: Using tacheometric methods, elevations can also be determined. It is in fact a branch of angular surveying in which both the horizontal and vertical positions of points are determined from the instrumental observations, the chain surveys being entirely eliminated.

5. Which of the following is the branch of angular surveying in which both the horizontal and vertical positions of points are determined from the instrumental observations, the chain surveys being entirely eliminated?
a) Tacheometry
b) Contouring
c) Ranging
d) Random line method

Explanation: Using tacheometric methods, elevations can also be determined. It is in fact a branch of angular surveying in which both the horizontal and vertical positions of points are determined from the instrumental observations, the chain surveys being entirely eliminated.

6. Tacheometer has ______ number of horizontal hairs.
a) 2
b) 3
c) 4
d) 5

Explanation: A tacheometer is similar to an ordinary transit theodolite, generally a vernier theodolite itself, fitted with two stadia wires in addition to the central cross-hair. The stadia diaphragm has three horizontal hairs viz., a central horizontal hair and upper and lower stadia hairs.

7. Which of horizontal hairs are equivalent in stadia diaphragm of tacheometer?
a) Upper and central
b) Central and lower
c) Upper and lower
d) Lower, central and upper

Explanation: The stadia diaphragm has three horizontal hairs viz., a central horizontal hair and upper and lower stadia hairs. The upper and lower stadia hairs are equidistant from the central horizontal hair. Stadia hairs are sometimes called stadia lines.

8. The magnification of the telescope in tacheometer should be at least _______ to _______ diameters.
a) 10 to 20
b) 10 to 30
c) 20 to 30
d) 20 to 40

Explanation: For the purpose of tacheometry, even though an ordinary transit can be employed, accuracy and speed are increased if the instrument is specially designed for the work. The magnification of the telescope in tacheometer should be at least 20 to 30 diameters.

9. What should be the aperture required for tacheometer?
a) 30mm
b) 40mm
c) 25mm
d) 15mm

Explanation: The magnification of the telescope in tacheometer should be at least 20 to 30 diameters, with an aperture of at least 40 mm for a sufficiently bright image.

10. The magnifying power of the eyepiece is also smaller than for an ordinary transit to produce a clearer image of a staff held far away.
a) True
b) False

Explanation: The magnifying power of the eyepiece is also greater than for an ordinary transit to produce a clearer image of staff held far away.

11. For short sights of about _____ m or less, an ordinary levelling staff may be used. For long sights, special staff called stadia rod is generally used.
a) 50
b) 100
c) 150
d) 200

Explanation: For short sights of about 100 m or less, an ordinary levelling staff may be used. For long sights, special staff called stadia rod is generally used. The graduations are in bold type (face about 50 mm to 150 mm wide and 15 mm to 60 mm thick) and the stadia rod is 3 m to 5 m long. To keep the staff or stadia rod vertical, a small circular spirit level is fitted on its backside. It is hinged to fold up.

12. In fixed hair method, the distance between _______ hair and__________ hair are fixed.
a) Upper and central
b) Central and lower
c) Upper and lower
d) Lower, central and upper

Explanation: In this method, the distance between the upper hair and lower hair, i.e. stadia interval i, on the diaphragm of the lens system is fixed. The staff intercepts, therefore, changes according to the distance D and vertical angle θ.

13. Distance and elevation formulae for fixed hair method assuming line of sight as horizontal and considering an external focusing type telescope is D = Ks + C. where K is _______
a) f/i
b) i/f
c) f + c
d) f – c

Explanation: The constant K is equal to (f /i). It is called multiplying constant of the tacheometer and is generally kept as 100. The constant C is equal to (f + c). It is called additive constant whose value ranges from 30 cm to 50 cm for external focusing telescopes and 10 cm to 20 cm for internal focusing telescopes.

14. For anallactic lens in D = Ks + C, which of the following is zero?
a) D
b) K
c) C
d) S

Explanation: The constant C is equal to (f + c). It is called additive constant whose value ranges from 30 cm to 50 cm for external focusing telescopes and 10 cm to 20 cm for internal focusing telescopes. For telescopes fitted with anallactic lens, C equals zero.

15. Distance and elevation formulae for fixed hair method assuming the line of sight as horizontal and considering an external focusing type telescope is D = Ks + C. where C is _______
a) f/i
b) i/f
c) f + c
d) f – c

Explanation: The constant K is equal to (f /i). It is called multiplying constant of the tacheometer and is generally kept as 100. The constant C is equal to (f + c). It is called additive constant whose value ranges from 30 cm to 50 cm for external focusing telescopes and 10 cm to 20 cm for internal focusing telescopes.

Sanfoundry Global Education & Learning Series – Surveying.

To practice all areas of Surveying, here is complete set of 1000+ Multiple Choice Questions and Answers.

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]