What is a local attraction meaning?

What is a local attraction meaning?

noun. A magnetic attraction near a compass , causing its needle to deviate from its proper direction, especially on shipboard.

Which station S is are affected by local attraction Examveda?

Which stations were affected by local attraction? Solution: As the difference between F.B and B.B of line AB is exactly 180°, stations A and B are free from local attraction which is not the case with line CD. Hence stations C and D are affected by local attraction.

What are the sources of errors in compass survey?

There are following errors in the compass surveying such as; Instrumental errors. Personal errors. Natural errors….Personal Errors:

• Inaccurate leveling.
• Inaccurate reading.
• Inaccurate centering.

What is magnetic bearing in surveying?

Magnetic bearing: The magnetic bearing of a line is the horizontal angle which it makes with the magnetic meridian passing through one of the extremities of the line.

How is local attraction corrected?

ADVERTISEMENTS: (ii) The observed bearings are corrected by applying correction to the stations affected by the local attraction. For this, error at each of the station is found and then starting from an unaffected bearing, the bearings of the successive lines are adjusted by applying corrections to them.

How local attractions can be detected?

Local attraction at a place can be detected by observing bearings from both ends of the line in the area. If fore bearing and back bearing of a line differ exactly by 180°, there is no local attraction at either station.

What is principle of compass surveying?

The Principle of Compass Survey is Traversing; which involves a series of connected lines the magnetic bearing of the lines are measured by prismatic compass and the distance (lengths) of the area measured by chain. Such survey does not require the formulation of a network of triangle.

What do you mean by local attraction?

Such a disturbing influence is called as local attraction. The external forces are produced by sources of local attraction which may be current carrying wire (magnetic materials) or metal objects. The term is also used to denote amount of deviation of the needle from its normal position.

What is local attraction in magnetic needle?

A freely suspended and properly balanced magnetic needle is expected to show magnetic meridian. However, local objects like electric wires and objects of steel attract magnetic needle towards themselves. Thus, needle is forced to show slightly different direction. This disturbance is called local attraction.

What is local attraction in magnetic compass?

Local attraction is the phenomenon by which the magnetic needle is constantly prevented to point towards the magnetic north at a place. This is because that these magnetic compass is influenced by other magnetic objects at that locality such as wires carrying electric current, rails, steel and iron structures, steel tapes etc.

How to minimize local attraction?

Local attraction can be minimized using following methods: This method is based on the difference of fore and back bearings. We already know that the difference between fore and back bearing of a line will be 180˚ if there is no errors in measurement.