Question

In a transit theodolite, any incidental error due to eccentricity of verniers is primarily counteracted by
1. Reading both the vernier
2. Reading different parts of main scale
3. Reading right and left faces
4. Taking both right swing readings

Answer 1

Correct Answer - Option 1 : Reading both the vernier

Concept:-

Error	Elimination Method
Horizontal axis not being perpendicular to vertical axis	Eliminated by reading angles from both the faces.
Line of collimation not being parallel to axis of telescope	Eliminated by taking reading from both faces.
Eccentricity of inner and outer axes	Eliminated by taking reading from both the Vernier and considering the average reading
Graduations not being uniform	Eliminated by measuring angles on different parts of circle.
Vernier being eccentric	Eliminated by reading both Vernier’s and taking the average.