337. The total change in level along the line is equal to total back sights
A. minus total fore sights
B. the total rises minus total falls
C. the reduced level of last point minus reduced level of the first point
D. all the above.

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338. The difference of level between a point below the plane of sight and one above, is the sum of two staff readings and an error would be produced equal to
A. the distance between the zero of gradient and the foot of the staff
B. twice the distance between the zero of graduation and the foot of the staff
C. thrice the distance between the zero of graduation and the foot of the staff
D. none of the above,

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339. If L is in kilometres, the curvature correction is
A. 58.2 L2 mm
B. 64.8 L2 mm
C. 74.8 L2 mm
D. 78.4 L2 mm.

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340. The combined effect of curvature and refraction over a distance L kilometres is
A. 67.2 L2 mm
B. 76.3 L2 mm
C. 64.5 L2 mm
D. none of these.

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341. Pick up the method of surveying in which field observations and plotting proceed simultaneously from the following
A. chain surveying
B. compass surveying
C. plan table surveying
D. tacheometric surveying.

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342. Which one of the following procedures for getting accurate orientation is the most distinctive feature of the art of plane tabling
A. radiation
B. intersection
C. traversing
D. resection.

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343. Contour lines of different elevations can unite to form one line, only in the case of
A. a vertical cliff
B. a saddle
C. a water shed line
D. a hill top.

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