Question

If L represents the staff reading and 'x' as the angle of inclination, error due to non-verticallity of the staff will be:
1. L(sin x - 1)
2. L(tan x - 1)
3. L(sec x - 1)
4. L(cosec x - 1)

Answer 1

Correct Answer - Option 3 : L(sec x - 1)

Explanation:

L = Staff Reading

X = Angle of inclination

So, if staff is vertical then reading on staff = L

if staff kept at an angle X then reading on staff = L sec X

Error due to non-verticallity of the staff = Measured value - True Value

Error due to non-verticallity of the staff = L sec X - L

Error due to non-verticallity of the staff = L (sec X - 1)