49) Which method gives approximate result and so it is adopted in the reconnaissance or in the preliminary survey?

50) What is the name of the levelling while the relative elevations of different points are obtained by measuring the vertical angles and horizontal distance?

51) What level is required for permanent adjustment if the bubble axis made parallel to collimation axis of the telescope?

52) What is the difference of level if dumpy level is at mid point C Staff reading on A = 1.580m Staff reading on B = 1.220m?

53) What is the height of collimation if reduced level of point A= 100.000m. Back sight at point A = 2.750m?