## Tuesday, July 16, 2013

### Questions from Surveying-1 which may be asked in viva and interview

Hi,
here are some questions which came into my mind that can be asked in your vivas or interviews.

Q.1 What is the principal of Surveying?
If you have studied the Surveying or if you are still studying, then this is the one of the first question which you should know. When ever you have to do any kind of survey you have to do it from whole to parts.

It is the first principle of Surveying. Initially main control points are established with very high accuracy at the far distances to cover whole the area and then using these points as the reference points you establish  the secondary and tertiary control points.

Second principle of Surveying which you should know is that any point can be established or located precisely with reference to a minimum of two another reference points. That means you need at least two reference points to locate one another point.

Q.2 What is the principal of chaining?
You must know that if you have to do the survey only with the help of chaining then it is done by triangulation. You have to divide the area into a numbers of triangles and measure its sides with the chain or tape.

Q.3 What is the height of a ranging rod and what is its diameter?
I think you will be rarely asked this question but putting a variety of ammunition always helps. Generally the height of a ranging rod is 2.4m but it may be varied up to 6m and its diameter is generally 1 inch. There are strips in red and white or red and yellow in the longitudinal direction which are generally 1ft length(30.5cm).

Q.4 What is the purpose of a level?
You know that level can be used for the levelling or sometimes for contouring too. So the basic purpose of a level is to provide a horizontal line of sight.

Q.5 What is the least count of a Theodolite?
You have to measure the horizontal and vertical angles using the Theodolite, so you must know that  least count is 10" to 20" (seconds) for a vernier theodolite but for a micro-meter theodolite least count may be as small as 0.l" .

Q.6 What are the sources of local attraction in Surveying?
First of all you must know that this term is related to the compass survey. Sometimes when you are doing the compass survey at places where there are materials which attract a magnetic needle of the compass, the magnetic needle fails to show the magnetic North accurately due to the attraction forces of these materials and therefore it will be deflected from true magnetic meridian.
It is important for you to know such materials which, may cause this error, right? This material can be a chain, a wrist band, a ring in your finger,   belt tide to your trouser, a hair band, a nearby electric pole or anything which attracts a magnet, so it might be needed for you know about magnets too.