Which one of the following pairs is not correctly matched?a)Declinatio...
Explanation:
The correct answer is option C: Reconnaissance: Employed for detailed and Survey precise survey.
Reconnaissance is a preliminary survey carried out to obtain a general idea of the area or region under consideration. It is performed before conducting detailed and precise surveys. Therefore, the pair "Reconnaissance: Employed for detailed and Survey precise survey" is not correctly matched.
Let's understand the other options for better clarity:
a) Declination: Horizontal angle between magnetic meridian and true meridian:
Declination refers to the angular difference between the magnetic meridian (direction indicated by a magnetic compass needle) and the true meridian (direction indicated by geographic or true north). This pair is correctly matched.
b) Bowditch's rule: Employed to adjust closing error of a closed traverse:
Bowditch's rule, also known as the compass rule, is used to distribute the closing error equally among the various angles of a closed traverse. It helps in adjusting the measured angles so that the sum of the interior angles equals the theoretical sum of 180 degrees. This pair is correctly matched.
d) Deflection angle: Measured in case of open traverse instead of measuring the included angle:
In an open traverse, where the starting and ending points are not the same, the deflection angle is used instead of measuring the included angle. The deflection angle is the angle between the forward bearing and the back bearing of a line. This pair is correctly matched.
In conclusion, the pair "Reconnaissance: Employed for detailed and Survey precise survey" is not correctly matched. Other options, such as declination, Bowditch's rule, and deflection angle, are correctly matched.