Which of the following represents a correct match?
i) moveable hair method - The intercept on levelling staff is kept constant and stadia hair interval is variable.
ii) fixed hair method - The intercept on levelling staff is variable and stadia hair interval is fixed.
iii) tangential hair method - The stadia hairs are not used.
1
Only (iii) is correct
2
only (i) and (ii) are correct
3
all (i), (ii) and (iii) are correct
4
none is correct