In levelling, error due to earth s curvature is to be corrected using:

1.	In levelling, error due to earth s curvature is to be corrected using:
A.	C<sub>c</sub>=0.0673D<sup>2</sup>
B.	C<sub>c</sub>=0.0112D<sup>2</sup>
C.	C<sub>c</sub>=0.0136D<sup>2</sup>
D.	C<sub>c</sub>=0.0785D<sup>2</sup>
Answer» E.

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