This set of Basic Civil Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Methods of Levelling”.
1. How many methods are used in levelling?
Explanation: The 2 methods are height of instrument method and rise and fall method. These are used to evaluate heights of various points.
2. How many types of levelling are there?
Explanation: There are 4 ways to perform levelling. They are direct levelling, trigonometric levelling, barometric levelling and stadia levelling.
3. Trigonometric levelling is also called:
a) Indirect levelling
b) Differential levelling
c) Fly levelling
d) Profile levelling
Explanation: In trigonometric levelling, the horizontal distance and vertical angle are measured from the station to the object. It uses trigonometric relations to compute vertical height of a point.
4. In _________ levelling, the first and last point are at a far distance.
Explanation: In differential levelling, a number of inter-stations are located and then instrument is shifted to each station and the elevation is observed.
5. Stadia levelling is a modified form of:
a) Fly levelling
b) Differential levelling
c) Simple levelling
d) Trigonometric levelling
Explanation: Tacheometer principle is used to determine elevation of points. Line of sight is inclined and it is more suitable for surveying in hilly terrains.
6. The last reading taken from the instrument is called:
a) End sight
b) Free sight
c) Fore sight
d) Back sight
Explanation: Fore sight (FS) is noted as last reading and back sight (BS) is noted as first reading taken from instrument. Any intermediate points are noted down as intermediate sight (IS).
7. Reciprocal levelling is used when,
a) Flat terrain
b) Obstacles are there
c) BM not visible
d) Highway construction
Explanation: If the points to surveyed lie on opposite banks of a river, reciprocal levelling can be used. It is done from both sides to eliminate chances of error.
8. In a hilly terrain, staff reading is more at:
a) Lower point
b) Higher point
c) First point
d) Last point
Explanation: In hilly terrain, the lowest point will give highest staff reading. It is at a lower level compared to others and hence has more height.
9. Which is the arithmetic check for height of instrument method?
a) ∑FS + ∑BS = First RL + Last [email protected]
b) ∑BS – ∑FS = Last RL – First [email protected]
c) ∑FS + ∑BS = Last RL + First [email protected]
d) ∑BS – ∑FS = First RL – Last [email protected]
Explanation: To check if the readings are written properly, an arithmetic check is done. The sum of back sight (BS) and Fore sight (FS) are subtracted. It should be equal to the difference of the last and first reduced level (RL).
10. Which instrument is used in trigonometric levelling?
a) Wye level
d) Dumpy level
Explanation: Trigonometric levelling involves measurements that are angular and hence requires an angle measuring instrument, like theodolite.
11. In levelling, error due to earth’s curvature is to be corrected using:
Explanation: Correction for earth’s curvature and refraction is to be applied. Cc is given by 0.0785D2. Combined correction Cc – Cr is given by 0.0673D2.
Sanfoundry Global Education & Learning Series – Basic Civil Engineering.
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