32) Which levelling instrument is required in second adjustment to make the line of collimation parallel to the axis of the bubble tube?

33) Which level instrument requires a signal permanent adjustment?

34) What is the postion of line of collimation, if observed staff reading is more than the required true staff reading?

35) What is the position of line of collimation While the observed reading is the less than the required true reading?

36) What is the diameter of earth?