# Civil Engineering - Surveying - Discussion

Discussion Forum : Surveying - Section 1 (Q.No. 26)
26.
In quadrantal bearing system, back bearing of a line may be obtained from its forward bearing, by
adding 180°, if the given bearing is less than 180°
subtracting 180°, if the given bearing, is more than 180°
changing the cardinal points, i.e. substituting N for S and E for W and vice-versa
none of these.
Explanation:
No answer description is available. Let's discuss.
Discussion:
29 comments Page 1 of 3.

AMUDALA VENKATESH said:   2 years ago
C is not the correct answer because quadrantal bearing taking with respect north or south only.

Rohan Mukherjee said:   4 years ago
In WCB, back bearing is obtained by BB=FB + or - 180, where subtraction is done when FB is more and addition is done when FB is less than 180.

In Reduced bearing system, or Quadrantal bearing system the numerical are same but the letters are put opposite.
(2)

R.k said:   4 years ago

Jinish patel said:   4 years ago
The horizontal angle made by a line with the magnetic north or south (whichever is closer from the line) in the eastward or westward direction is the Quadrantal Bearing or Reduced Bearing of the line.

SO option C (changing the cardinal points, i.e. substituting N for S and E for W and vice-versa) is right
(1)

Bheem said:   5 years ago
@Sandeep.

It is quadrant bearing. Not a wcb.

Sumit said:   5 years ago

Sumit said:   5 years ago
For whole circle Bearing:

BB = FB +-180.
BB = FB +180 (LESS THAN 180).
BB = FB -180 ( MORE THAN 180).

FOR QB SYSTEM:

BB = FB (BUT ONLY DIRECTION CHANGE).
N - S.
S - N.
E - W.
W - E.

Jyoti said:   5 years ago